[Distributed Consensus]

With various innovative consensus mechanisms such as PoS, DPoS and PBFT emerging in the blockchain world, some people are asking “is PoW outdated?”, “what is the future of PoW?”, “is it still meaningful to do some optimization and innovation work based on PoW?”

After much research and analysis, YeeCo team believes that PoW is still the basis or the kernel of other existing consensus mechanisms and holds an irreplaceable position. Here is our analysis and thoughts on the essential advantages of PoW consensus.

Distributed Consensus

When Satoshi Nakamoto came up with the PoW consensus, he didn’t mean to further the research on distributed consensus done by the scholars. People intend to consider that his PoW consensus provides a solution for distributed consensus in Byzantine environment, giving it an academic perspective, and we start to connect them together.

Speaking of the distributed consensus, we have to include "FLP impossible" theorem in our discussion. "FLP impossible" theorem is come up with and proven by three scientists, Fischer, Lynch and Patterson, in their paper "Impossibility of Distributed Consensus with One Faulty Process” in 1985. The theorem concludes that there is no deterministic consensus algorithm that can solve the consistency problem in a minimum asynchronous model system that is reliable in the network but allows node failure (even if there is only one). The revelation of this theorem is that the technically workable distributed consensus must be compromised in some respects.

In fact, there are mainly 2 types of compromise; one is the compromise of asynchrony, and the other is the compromise of finality.

The compromise of asynchrony is to set the timeout mechanism, assuming that the message will not be infinitely delayed. The DLS algorithm (“Consensus in the Presence of Partial Synchrony”) and the PBFT algorithm (“Practical Byzantine Fault Tolerance”) are examples in this. Furthermore, the DLS paper reveals two goals of asynchronous consensus in the Byzantine environment: security (consistency) and liveness (availability). Both of the examples make synchronization assumptions to ensure liveness rather than security, which means that if the real environment does not meet the synchronization hypothesis, it will only cause liveness problems rather than consistency problems. That's why we often say that PBFT is a consensus algorithm that prioritizes consistency over availability.

The compromise of finality is based on the concept introduced by Nakamoto, which is that finality is probabilistic. A probabilistically secure consensus is jointly constructed by peer-to-peer networks  through the proof of work and block rewards. It seems that on the map, the Nakamoto consensus is only one of the 2 compromise solutions of the asynchronous Byzantine consensus problem defined by consensus researchers, but the introduction of probability finality not only solves the traditional asynchronous Byzantine problem, but also solves a bigger problem. : Allows any number of nodes to participate in the system in an open manner, and they don’t have to know the complete set of the participants. It is very remarkable because this is the reality that the public chains face. In practice, the Nakamoto consensus that makes compromise on finality has achieved great success.

In essence, the innovative consensuses are also based on the 2 types of compromises.

The Compromises Made by Various Consensuses

PoS

PoS is essentially a PoW and it is a kind of compromise of finality. Staking can be regarded as a threshold. By introducing the threshold, the number of the participants is reduced. The smaller participant set size has two advantages: 1. The total workload of the entire system will be reduced, so is the energy consumption; 2. Asynchronous communication networks are smaller in scale and a fork is less likely to happen due to the delay, and block intervals can be smaller. This is why PoS says it has higher TPS and is more efficient.

DPoS+PBFT

DPoS+PBFT is PBFT in nature and it’s a kind of compromise of asynchrony. The purpose of DPoS is to select a set of participants that can apply the PBFT algorithm. This set has to meet three conditions: 1. The scale is small enough, otherwise the traffic is huge; 2. The total number of the participants is a certain figure, so it is an asynchronous consensus problem that PBFT can solve; 3. The number of malicious participants (Byzantine nodes) is less than 1/3. The Staking mechanism plays two roles in it: 1. Screening users as a threshold; 2. As an incentive mechanism to reduce the proportion of malicious nodes.

Tetris

Tetris is a knowledge inference based consensus algorithm innovated by YeeCo. It is essentially BFT and a kind of compromise of asynchrony. Tetris itself is a solution to the standard Byzantine problem, with a focus on its high performance and proven security. The BFT participants are selected through a pluggable upper layer protocol, which is workable in PoW, DPoS, VRF, etc.

Algorand

Algorand is essentially a BFT, a kind of compromise of asynchrony. Algorand chooses a set of participants that can apply the BFT algorithm in a very special and ingenious way, using VRF (verifiable random function), similar to each participant owning a lottery ticket and the participant can know if he/she is selected or not without communicating with other participants. It seems to be very efficient, but there are a few limits: 1. Need to set a threshold for the participants, because the cost of creating a private key to participate in the network is very low, and in fact Algorand takes the participant’s balance into consideration; 2. As there should be a winning rate for the lottery, and the system needs to know the total number of participants whic is a consensus problem in itself. In order to infer the total number of participants, Algorand tries to make sure that the online balance is about the same as the total balance in the network by rewarding the online nodes. This is in fact a Byzantine fault tolerant system that requires that the total balance of the online and honest nodes is  over 2/3.

DAG

DAG (Directed Acyclic Graph), adopted by IOTA and Conflux, is essentially PoW, and a compromise of finality. If the previous consensuses aim to avoid forks, then DAG’s aim is to control the fork to a certain level, thereby improving the system’s TPS. The essence of DAG is proof of work, but the principle of the longest chain has been changed to the principle of  the most difficult graph structure.

PoW Being the Kernel or Basis

The difference in the various consensus mechanisms is actually the difference in the path from “an open set of network participants” to “consensus”. For example, if the path is from “an open set of network participants” directly to “consensus”, then it is PoW; if the path is from “an open set of network participants” to “an open set of ledger keepers” first and then to "consensus", then it is PoS; if the path is from “an open set of network participants” to “a closed set of ledger keepers” first and then to “consensus”, then it is X+BFT, and X may be DPoS or VRF.

We can see that there are not much innovation in these consensus mechanisms. As long as a consensus is reached from an “an open set of network participants" (nodes can join and leave freely), only one model can be adopted, Nakamoto consensus: nodes are motivated to continue to reach a consensus result based on a consensus result with probabilistic finality.

The meaning of PoW to other consensuses lies in 2 points:

If the consensus is constructed from “an open set of network participants” (nodes can join and leave freely), then it is essentially Nakamoto consensus, so PoW consensus is regarded as the kernel of such consensuses.
If the consensus is changing “an open set of network participants” to “a closed set of network participants”, then mechanism is still required in this case. Where does the consensus on the value of staking come from? The first crypto currency and the Nakamoto consensus play important roles in it. So PoW consensus plays as the basis of such consensuses.

The Essential Advantages of PoW

PoW supporters has listed a number of its merits, such as reliability, purity. When it comes to energy consumption, some people regard it as a flaw, while some people disagree and believe that energy cost is the basis of security.

From my point of view, the essential advantages of PoW are as follows:

Ultimate Openness

PoW is designed for an open set of participants. This openness (the participants are unstable) is always a challenge for them to reach a consensus, whether it is during the earliest cold start, or during the mining stage when the crypto price and mining difficulty are fluctuating.

PoW has adopted an extremely simple mechanism to solve the openness problem. PoW does not need to make any patches for any of the scenarios or conduct any governance. Relying on its core mechanism to drive the entire system, it has withstood the test of time. PoW consensus design is ingenious, simple and adaptable, making it outstanding among a number of consensuses.

PoW is an absolute permissionless system. New hashrate can join the competition at any time and at the same starting line with existing hashrate. Although Staking investments seem similar to the hashrate investments, but different initial factors lead to quite different situations. If the blockchain system is a system that is easy to fall into the "Matthew effect", then in PoW the requirement of hashrate investments (external and physical) is an important factor to resist this effect. On the one hand, the lagging adjustment mechanism makes it difficult for the system to enter a steady state. On the other hand, the external and physical hashrate investments are more independent than stakings. For PoW, the positive feedback of the consensus advantage of influencing the consensus result to the business advantage is one-way, but for staking, the positive feedback is two-way.

Ultimate Security

The frequently discussed security issues, such as 51% attack, over 1/3 Byzantine nodes, are all issues that may arise due to the consensus rules. However, the blockchain system is ultimately a system running on a physical network, so, compared with the attack that takes advantage of the consensus rules, the attack at the physical network level would be a catastrophe to the blockchain system.

PoW believes that the power of a node should not be determined by the virtual resource it holds(Staking), but should be determined by the physical resource (hashrate).

In the case of Staking, it is easy to fall into a situation where the size of the network nodes doesn’t grow with the continuous investment of virtual resources due to the lack of driving force. The economic scale of the system and its resistance to threats from the network are not matched, and there is no internal mechanism to promote that.

In the case of PoW, the resource investments correspond to the investments to power of influence in the network. At the initial stage, the hashrate investment is to invest more nodes. Later, with the emergence of professional mining machines and mining pools,  the hashrate and the node count do not match exactly. But since the hashrate is invested, the investors will definitely take measures to get the power of influence in the network, and the economic scale of the system and its resistance to threats from the network are matched. If virtual resources are attached more importance to when weighting the node, the difference between the power of influence in the system and that in the physical network for the nodes will be greater. As for the PoW that doesn’t take the virtual resources into consideration at all, the power of influence in the system and that in the physical network for the nodes are the same. The security of PoW is reflected here: energy cost being the basis of security is resulted from the physical network environment.

Openness and security are exactly the two angles in the “blockchain impossible triangle” (in the triangle that’s formed by Scalability, Decentralization, and Security, there are only two angels can be achieved).

The essential advantages of PoW is that it provides a highly decentralized and secure consensus mechanism. And the one that’s left, scalability, is exactly the development and innovation direction of the PoW consensus.

This article is written by YeeCo CTO. Please feel free to share your thoughts below.

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[The Finality of Different Consensus Mechanisms]

With the development of the blockchain technology, especially the continuous exploration of new technologies such as low-latency chain and cross-chain, finality has been discussed and studied in more cases. Before we start the discussion of finality design, let us first understand what is finality.

The literal meaning of finality is immutability, and is a more ancient concept than “decentralization” and “consensus”. Since the birth of ledger, people can discuss and define its finality, which has nothing to do with any technical issues, because ledger at that time is centralized (with a trust intermediary), and like correctness, finality is also the reflection of the will of the intermediary.

Only after the blockchain technology introduces the decentralized ledger, consensus and finality become technical issues, and we may face situations where finality and consensus cannot be achieved at the same time.

The Finality of Different Consensus Mechanisms

According to the current research, we have evaluated the finality of various consensus mechanisms.

For example, PoW does not have absolute finality, only probabilistic finality; BFT has absolute finality, so does Casper FFG. YeeCo’s Tetris consensus also has absolute finality.

Why do different consensus mechanisms have different levels of finality, and what are the factors responsible for that?

The Principle of Finality

What is the nature of consensus? Consensus is the process by which people who want to achieve consistency successfully achieve that, and consensus mechanism ensure that people who want to achieve consistency can still achieve consistency when there is a communication barrier or someone misleading other people.

There is something very interesting in it, a bit of a word game, which is, “people who want to achieve consistency” appears as a precondition in some consensus mechanisms (first determine who want consistency, then seek the consistency ), while in some other consensus mechanisms, it appears as the result (claim the consensus of certain participators, never promise it is the consensus of all people though).

For example, a company wants to hold a dinner party, and all of the employees should reach a consensus on where to hold it. The first approach is “authorities have the final say”, which means if the leaders of the company could reach a consistency, then the whole company reach a consensus. The second approach is that some employs reach a consensus first, and then announce it in the company, but if some powerful people vote against it, then the consensus will be changed; it would keep going until all of the employees reach a consensus.

Both approaches can achieve consensus in some degree, but what about the finality? Regarding the first approach, the consensus has absolute finality since it can’t be changed as soon as it’s reached. Regarding the second approach, the consensus has probabilistic finality, since it can be modified theoretically, though with a verify low probability.

The example actually demonstrates the difference between the BFT consensus and the PoW consensus. Put it in technical language: the BFT consensus first assumes there is a stable consensus range, and on this basis, choose a strong consistency but low liveness mechanism, thus achieving absolute finality; the PoW consensus does not assume a stable consensus range, and the consensus participants can enter and exit at any time. On this basis, a mechanism with high liveness and eventual consistency is adopted, but it still doesn’t have absolute finality. Therefore, the consensus range is the key to determine the essential nature of finality.

The Necessity of Absolute Finality

As the transactions on the blockchain often represent the ownership transfer of properties, the fact that the transaction can be modified would be fatal to these economic activities. Double spend attack happens through taking advantage of PoW not having absolute finality.

Applications associated with the blockchain is operating based on some kind of finality criteria, such as the well-known Bitcoin 6 confirmations and the Ethereum 12 confirmations. However, things do not always work like that. Everyone can recall that when a fork, a hashrate war, or an attack occurred, the wallets and the exchanges suspended the transactions. This indicates the finality of the PoW is evaluated as vulnerable under such circumstances, so the n-confirmed standard will be adjusted to infinite confirmed standard.

Cross-chain and multi-chain sharding are also forms of applications associated with the blockchain. Their requirements for finality are much higher than off-chain applications:

Blockchain is a system that operates according to programmed procedures and cannot modify the n-confirmed criteria actively as in the case of off-chain applications.
In terms of double spend attack, it is not easy to find a trading target large enough in the off-chain application. There is not much profit in it and the cost is high, so it is difficult to carry out the double spend attack. However, it is easy to find a trading target large enough in the cross-chain, and the attack becomes profitable.
Therefore, from the perspective of application supporting, the blockchain should be responsible and provide finality, rather than letting the applications evaluate the finality degree by themselves. From the perspective of cross-chain supporting, the security of cross-chain is based on finality. In a word, absolute finality is vital and necessary.

Consensus Participants’ Game under Absolute Finality

Regarding the consistency of the consensus, if the consensus participants can still agree with the “authorities have the final say” principle (for BFT, it is the collection of voters; for PoW, it is the hashrate), then even if the consensus does not meet their own wishes, they will still choose to “obey”; if the consensus participants do not agree with the principle, then there would be a hard fork.

When absolute finality is introduced, let’s take a look at what it means for a consensus with strong consistency and a consensus with eventual consistency.

For the consensus with strong consistency, like that of BFT, strong consistency and absolute finality are a whole. The consensus itself can’t build an alternative chain. Usually an alternative chain is built due to some interference. If some voters made a hard fork happen and build an alternative chain, the finality of the old chain is still guaranteed, and as long as the new chain has its own users, these users also recognize the finality of the new chain. If the collectors collude to rebuild the chain through hard forks, the original chain is discarded, and it seems that the applications on the original chain is affected by the modification of the block, but it is not due to the destruction of the finality, it’s simply due to the death of the original chain.

For the consensus with eventual consistency, like that of PoW, the rebuildability of the chain is preserved in order to support the unstable consensus range. If absolute finality is introduced, a new stable consensus range must have been introduced. In order to ensure the finality of a block, the operation of PoW can’t be just following the longest chain principle. Rather, it should follow the principle of “the longest chain containing the finalized block”, that is, even if the super hashrate has the ability to rebuild the chain, it should also”obey” the new stable consensus range, and if the super hashrate is unwilling to obey, then it can make a hard fork, in which case the finality of the original chain is still guaranteed. The willingness to obey of the the super hashrate is related to the authority of the “new stable consensus range”. If it has little authority, it is likely for the super hashrate not to obey, in which case, the situation would be a complicated one regarding how the applications would choose, stick with the old chain or switch to the hard fork.

From the above analysis we can learn that absolute finality can lead to two extremes. One is to reach a consistency that cannot be modified; the other is that if a consistency can’t be reached, it will be split into two different consistencies that can’t be modified, and the applications have to choose one between two and recognize the finality of the consistency it picked.

Since there are two extreme cases, when we design the finality mechanism, we should try to avoid the case that can lead to hard forks. We will discuss the finality design of the PoW consensus mechanism in the next part.

In summary, from the perspective of applications, absolute finality turns the risk of block being modified into the risk of blockchain fork, which in turn affects the consensus participants’ game. If such impact can further reduces the possibility of blockchain fork, it would be a successful finality mechanism and that would be very valuable for the applications.

The Finality Design of the PoW Consensus Mechanism

The classic PoW consensus adheres to the adoption of the unstable consensus range and the principle of the longest chain, and retains the possibility that super hashrate is able to rebuild the chain to achieve new consistency. If we still insist on these, it is theoretically impossible to establish absolute finality, so we should choose a reasonable way to break these limits.

The absolute finality design of PoW consensus mechanism should include the following points:

1. The establishment of stable consensus range

As mentioned above, the essential requirement of absolute finality is a stable consensus range. The question is how to introduce one, whether we should directly transform the unstable consensus range in PoW and combine the two ranges into one, or introduce a new one and make them run side by side?

How much influence does the stable consensus range have on the decentralization of PoW, and will it weaken the authority of the hashrate so that the PoW actually degenerates into a voting mechanism?

2. The establishment timing of finality

Should we establish it and consistency at the same time, or at different times? If at different times, how long should finality be delayed? In theory, the shorter the delay is, the more it is needed for the unstable consensus range (hashrate) to obey the stable consensus range. How to balance them then?

3. Make stable consensus range compatible with the incentive mechanism

The stable consensus range is generated by some mechanism, such as Staking. As voting on finality determines the direction of the chain, voters can choose to vote on both sides without any loss. This is nothing at stake problem. How to avoid this problem through incentive mechanism?

4. Failure governance mechanism

The establishment of finality is to obtain a strong consistency at the cost of liveness, then it will certainly encounter a situation where the consensus on finality cannot be achieved. The advantage of this situation is that it reflects the responsible side of the chain. The height of the finalized block no longer grows, and the off-chain activities will be suspended accordingly. The downside is that a governance mechanism is needed to resolve the failure of reaching a consensus on finality.

5. Support multi-chain sharding

Off-chain applications need safe access to finality information. The regular way is to run a full node, synchronize finality consensus results and verify. In the multi-chain sharding scenarios, usually each sharding runs the full node of its own and light nodes of all other shardings. This brings out a problem, whether a light node can safely synchronize the finality consensus results. It is an important problem that needs to solve in order to achieve multi-chain sharding.

In addition, if a sharding chain is forked, how to make other shardings identify which is the original chain and which is the forked chain, and ensure that they only interacts with one chain unanimously.

YeeCo’s CRFG (Conditional Reward Finality Gadgets) proposes a set of solutions for establishing absolute finality on the PoW consensus mechanism, which will be elaborated in the subsequent articles.


How do you guys think of the PoW consensus? Join me in the discussion.

[The Finality of Different Consensus Mechanisms]

With the development of the blockchain technology, especially the continuous exploration of new technologies such as low-latency chain and cross-chain, finality has been discussed and studied in more cases. Before we start the discussion of finality design, let us first understand what is finality.

The literal meaning of finality is immutability, and is a more ancient concept than “decentralization” and “consensus”. Since the birth of ledger, people can discuss and define its finality, which has nothing to do with any technical issues, because ledger at that time is centralized (with a trust intermediary), and like correctness, finality is also the reflection of the will of the intermediary.

Only after the blockchain technology introduces the decentralized ledger, consensus and finality become technical issues, and we may face situations where finality and consensus cannot be achieved at the same time.

The Finality of Different Consensus Mechanisms

According to the current research, we have evaluated the finality of various consensus mechanisms.

For example, PoW does not have absolute finality, only probabilistic finality; BFT has absolute finality, so does Casper FFG. YeeCo’s Tetris consensus also has absolute finality.

Why do different consensus mechanisms have different levels of finality, and what are the factors responsible for that?

The Principle of Finality

What is the nature of consensus? Consensus is the process by which people who want to achieve consistency successfully achieve that, and consensus mechanism ensure that people who want to achieve consistency can still achieve consistency when there is a communication barrier or someone misleading other people.

There is something very interesting in it, a bit of a word game, which is, “people who want to achieve consistency” appears as a precondition in some consensus mechanisms (first determine who want consistency, then seek the consistency ), while in some other consensus mechanisms, it appears as the result (claim the consensus of certain participators, never promise it is the consensus of all people though).

For example, a company wants to hold a dinner party, and all of the employees should reach a consensus on where to hold it. The first approach is “authorities have the final say”, which means if the leaders of the company could reach a consistency, then the whole company reach a consensus. The second approach is that some employs reach a consensus first, and then announce it in the company, but if some powerful people vote against it, then the consensus will be changed; it would keep going until all of the employees reach a consensus.

Both approaches can achieve consensus in some degree, but what about the finality? Regarding the first approach, the consensus has absolute finality since it can’t be changed as soon as it’s reached. Regarding the second approach, the consensus has probabilistic finality, since it can be modified theoretically, though with a verify low probability.

The example actually demonstrates the difference between the BFT consensus and the PoW consensus. Put it in technical language: the BFT consensus first assumes there is a stable consensus range, and on this basis, choose a strong consistency but low liveness mechanism, thus achieving absolute finality; the PoW consensus does not assume a stable consensus range, and the consensus participants can enter and exit at any time. On this basis, a mechanism with high liveness and eventual consistency is adopted, but it still doesn’t have absolute finality. Therefore, the consensus range is the key to determine the essential nature of finality.

The Necessity of Absolute Finality

As the transactions on the blockchain often represent the ownership transfer of properties, the fact that the transaction can be modified would be fatal to these economic activities. Double spend attack happens through taking advantage of PoW not having absolute finality.

Applications associated with the blockchain is operating based on some kind of finality criteria, such as the well-known Bitcoin 6 confirmations and the Ethereum 12 confirmations. However, things do not always work like that. Everyone can recall that when a fork, a hashrate war, or an attack occurred, the wallets and the exchanges suspended the transactions. This indicates the finality of the PoW is evaluated as vulnerable under such circumstances, so the n-confirmed standard will be adjusted to infinite confirmed standard.

Cross-chain and multi-chain sharding are also forms of applications associated with the blockchain. Their requirements for finality are much higher than off-chain applications:

Blockchain is a system that operates according to programmed procedures and cannot modify the n-confirmed criteria actively as in the case of off-chain applications.
In terms of double spend attack, it is not easy to find a trading target large enough in the off-chain application. There is not much profit in it and the cost is high, so it is difficult to carry out the double spend attack. However, it is easy to find a trading target large enough in the cross-chain, and the attack becomes profitable.
Therefore, from the perspective of application supporting, the blockchain should be responsible and provide finality, rather than letting the applications evaluate the finality degree by themselves. From the perspective of cross-chain supporting, the security of cross-chain is based on finality. In a word, absolute finality is vital and necessary.

Consensus Participants’ Game under Absolute Finality

Regarding the consistency of the consensus, if the consensus participants can still agree with the “authorities have the final say” principle (for BFT, it is the collection of voters; for PoW, it is the hashrate), then even if the consensus does not meet their own wishes, they will still choose to “obey”; if the consensus participants do not agree with the principle, then there would be a hard fork.

When absolute finality is introduced, let’s take a look at what it means for a consensus with strong consistency and a consensus with eventual consistency.

For the consensus with strong consistency, like that of BFT, strong consistency and absolute finality are a whole. The consensus itself can’t build an alternative chain. Usually an alternative chain is built due to some interference. If some voters made a hard fork happen and build an alternative chain, the finality of the old chain is still guaranteed, and as long as the new chain has its own users, these users also recognize the finality of the new chain. If the collectors collude to rebuild the chain through hard forks, the original chain is discarded, and it seems that the applications on the original chain is affected by the modification of the block, but it is not due to the destruction of the finality, it’s simply due to the death of the original chain.

For the consensus with eventual consistency, like that of PoW, the rebuildability of the chain is preserved in order to support the unstable consensus range. If absolute finality is introduced, a new stable consensus range must have been introduced. In order to ensure the finality of a block, the operation of PoW can’t be just following the longest chain principle. Rather, it should follow the principle of “the longest chain containing the finalized block”, that is, even if the super hashrate has the ability to rebuild the chain, it should also”obey” the new stable consensus range, and if the super hashrate is unwilling to obey, then it can make a hard fork, in which case the finality of the original chain is still guaranteed. The willingness to obey of the the super hashrate is related to the authority of the “new stable consensus range”. If it has little authority, it is likely for the super hashrate not to obey, in which case, the situation would be a complicated one regarding how the applications would choose, stick with the old chain or switch to the hard fork.

From the above analysis we can learn that absolute finality can lead to two extremes. One is to reach a consistency that cannot be modified; the other is that if a consistency can’t be reached, it will be split into two different consistencies that can’t be modified, and the applications have to choose one between two and recognize the finality of the consistency it picked.

Since there are two extreme cases, when we design the finality mechanism, we should try to avoid the case that can lead to hard forks. We will discuss the finality design of the PoW consensus mechanism in the next part.

In summary, from the perspective of applications, absolute finality turns the risk of block being modified into the risk of blockchain fork, which in turn affects the consensus participants’ game. If such impact can further reduces the possibility of blockchain fork, it would be a successful finality mechanism and that would be very valuable for the applications.

The Finality Design of the PoW Consensus Mechanism

The classic PoW consensus adheres to the adoption of the unstable consensus range and the principle of the longest chain, and retains the possibility that super hashrate is able to rebuild the chain to achieve new consistency. If we still insist on these, it is theoretically impossible to establish absolute finality, so we should choose a reasonable way to break these limits.

The absolute finality design of PoW consensus mechanism should include the following points:

1. The establishment of stable consensus range

As mentioned above, the essential requirement of absolute finality is a stable consensus range. The question is how to introduce one, whether we should directly transform the unstable consensus range in PoW and combine the two ranges into one, or introduce a new one and make them run side by side?

How much influence does the stable consensus range have on the decentralization of PoW, and will it weaken the authority of the hashrate so that the PoW actually degenerates into a voting mechanism?

2. The establishment timing of finality

Should we establish it and consistency at the same time, or at different times? If at different times, how long should finality be delayed? In theory, the shorter the delay is, the more it is needed for the unstable consensus range (hashrate) to obey the stable consensus range. How to balance them then?

3. Make stable consensus range compatible with the incentive mechanism

The stable consensus range is generated by some mechanism, such as Staking. As voting on finality determines the direction of the chain, voters can choose to vote on both sides without any loss. This is nothing at stake problem. How to avoid this problem through incentive mechanism?

4. Failure governance mechanism

The establishment of finality is to obtain a strong consistency at the cost of liveness, then it will certainly encounter a situation where the consensus on finality cannot be achieved. The advantage of this situation is that it reflects the responsible side of the chain. The height of the finalized block no longer grows, and the off-chain activities will be suspended accordingly. The downside is that a governance mechanism is needed to resolve the failure of reaching a consensus on finality.

5. Support multi-chain sharding

Off-chain applications need safe access to finality information. The regular way is to run a full node, synchronize finality consensus results and verify. In the multi-chain sharding scenarios, usually each sharding runs the full node of its own and light nodes of all other shardings. This brings out a problem, whether a light node can safely synchronize the finality consensus results. It is an important problem that needs to solve in order to achieve multi-chain sharding.

In addition, if a sharding chain is forked, how to make other shardings identify which is the original chain and which is the forked chain, and ensure that they only interacts with one chain unanimously.

YeeCo’s CRFG (Conditional Reward Finality Gadgets) proposes a set of solutions for establishing absolute finality on the PoW consensus mechanism, which will be elaborated in the subsequent articles.

区块链共识的确定性设计

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随着区块链技术的发展，特别是低延迟链，跨链等新技术的不断探索，确定性（Finality）越来越多的被讨论和研究。在开始本文的讨论之前，我们先理解下什么是确定性。

确定性字面意思是不可改变性，是比“去中心化”，“共识”更古老的概念。 从有账本开始，就可以探讨和定义其确定性，而此确定性不面临任何技术问题，因为那个时候的账本都是中心化的（有信任中介），确定性和正确性一样，都是信任中介意志的反映。

而只有在区块链技术引入了去中心化账本之后，共识和确定性才成为一个技术问题，我们可能面临确定性和共识无法同时达到的情况。

不同共识算法的确定性

[/b]

根据目前的研究，大家对各类不同共识算法的确定性有了评估。

比如PoW不具有绝对确定性（Absolute Finality），只具有概率确定性（Probabilistic Finality），BFT具有绝对确定性，Casper FFG具有绝对确定性，YeeCo团队的Tetris共识具有绝对确定性。

为什么不同共识算法的确定性水平不同，是什么内在特性起作用呢？

确定性的原理

[/b]

共识的本质是什么？共识是想要达成一致性（Consistency）的人达成一致性的过程，共识算法保证了想要达成一致性的人在有通信障碍或有人从中误导的情况下仍然可以达到一致性。

这里面有一个很好玩的点，有点文字游戏的意思，那就是“想要达成一致性的人”在某种共识机制中是作为前提条件出现的（先确定哪些人想达成一致，再寻求一致），而在某种其他共识机制中是作为共识结果出现的（达到一致但也注明范围，永远不承诺是所有人的共识）

举个例子，假设要为全公司组织一次聚餐，需要就去哪吃饭达成共识，第一种做法的思路是这事是公司“说的算的人”才能决定的，把这些人选定，投票，形成共识；第二种做法的思路是，公司水有多深，咱也不知道，咱也不敢问，到底是老板说的算，还是老板的小秘说的算，还是扫地僧说的算，姑且先形成一个不成熟的共识，然后公示出来，坐等有更大权力的人出来纠正，如果公示期足够长，就相信最终能达成一致，形成共识。

目前两种做法都算是达成了共识，但是他们在确定性上的表现如何呢？第一种做法的共识已经是公司“说的算的人”的决定，当时要么达成了一致，那就可以不修改了，要么就没达不成一致，悬而未决，总之不会出现先公布一个结果又修改的情况；第二种做法的共识是不断被纠正的，越往后被纠正的成本越高，概率越低，但理论上仍然可能被修改。

上述例子其实描述了BFT共识和PoW共识的不同，换成技术的语言说就是：BFT共识先假定一个稳定的共识范围，在此基础上选择一种强一致性但是低活性（Liveness）的机制，强一致性可以实现绝对确定性；PoW共识不假定稳定的共识范围，认为共识参与者可以随时进出，在此基础上只能采取一种高活性但是只具有最终一致性的机制，而最终一致性不能实现绝对确定性，只能实现概率确定性。

所以，决定确定性的本质特性是共识范围，这也符合大众的直觉观念，所谓共识范围就是“谁说的算”，“谁说的算”确定，你就会相信结果不会被修改，“谁说的算”不确定，你就不会相信结果不会被修改，这也就是大家口中说的：生意要跟“说的算的人”谈。

绝对确定性的必要性

因为区块链上的交易往往对应链下世界的权属转移（比如支付，充值等等），交易可被修改对这些经济活动的破坏是致命的，双花攻击实质就是利用了PoW不具有绝对确定性。

和链关联的应用在实践中还是基于某种确定性的标准在工作，比如大家熟知的比特币6个确认，以太坊12个确认。但这个确定性标准并不完整，大家可以回忆当发生分叉，算力战，攻击等情况下，钱包和交易所都会主动暂停交易，相当于这些应用评估PoW的确定性在这些特殊情况下减弱了，于是主动把n-confirm的标准调整到无穷大个确认。

跨链和多链分片也是和链关联的应用的一种表现形式，只不过链之间互为应用，他们对确定性的要求比链下应用更高，体现在两点：

区块链是一套按既定程序运行的系统，并不能像链下应用那样通过评估主动修改n-confirm的标准。
双花攻击中，链下应用很难找到足够大的交易物，收益不足而成本很高，双花实际很难被采用，但是跨链时链上很容易找到足够大的交易物，收益提升，双花变得有利可图。
所以，一方面从支撑应用的角度，链应该提供负责任的确定性，而不是把评估确定性的工作推给应用，另一方面从支持跨链的角度，确定性是其安全性的基石。 实现绝对确定性是必要的。

绝对确定性下共识参与者的博弈

[/b]

单看共识的一致性，如果共识参与者还能做到认同“谁说了算”（BFT里是投票人集合，PoW里是算力），那么若共识结果符合自己的意愿，则皆大欢喜，若共识结果不符合自己的意愿也会选择“服从”；如果共识参与者已经不认同“谁说了算”了，则会选择硬分叉。

当引入了绝对确定性后，我们看一下对于强一致性共识和最终一致性共识分别意味着什么。

对于BFT这种强一致性共识，强一致性和绝对确定性是一体的，共识本身没有重铸链的情况，发生重铸链都是因为被干预，如果是部分投票人通过硬分叉分裂了链，老的链上的块的确定性仍然是得到保证的，只不过新分叉出一条链，这条新链只要有用户，这些用户也是认可这条新链上的块的确定性的； 如果是投票人集合合谋通过硬分叉重铸链，之前的链被废弃了，看起来依赖之前链的应用受到了区块被修改的影响，实际这种影响是因为老链死亡，而不是因为老链上的区块的确定性被破坏。

对于PoW这种最终一致性共识，链的可被重铸性是为了支持不稳定的共识范围而保留的，如果引入了绝对确定性，按前面的论述一定是额外引入了稳定的共识范围，那为了保证一个块的确定性，PoW的运行方式就不能仅仅是最长链原则，而只能是“包含被确定的块的最长链”原则，即大算力即使具备重铸链的能力，也要“服从”那个建立了确定性的稳定共识范围，而如果大算力不愿意服从，则只能发起硬分叉，老的链上的块的确定性仍然是得到保证的。大算力服从的意愿与“额外引入的稳定的共识范围”的权威性有关，如果不够权威，则大算力不服从的可能性就很大，应用是跟着确定性的共识范围走还是跟着大算力走就成了一个很复杂的情况了。

通过上诉的场景分析，我们可以理解到绝对确定性是不收敛的，是一致性的两个极端，一个极端是达成一致且不修改，一个极端是达不成一致就分裂成两个都不修改的部分，应用要在两个部分中做出选择，选择哪部分就认可哪部分的确定性。

既然有两个极端情况，我们设计确定性机制的时候，就要尽量让博弈结果能够均衡到不分裂的那种结果，后面会讨论PoW共识中确定性的设计。

总结来看，从应用的视角，绝对确定性的价值在于把区块可被改变的风险转化成了区块链分叉的风险，这种转变反过来又影响共识参与人的博弈行为，如果这种影响又进一步降低了分叉的可能性，则是一个成功的确定性机制，对应用来说是非常有价值的。

PoW共识中的确定性设计

[/b]

经典的PoW共识坚持不稳定的共识范围这一设定，坚持最长链原则，保留了大算力进来重铸链而达到新的一致性的可能，如果我们仍然坚持这些，理论上是无法建立绝对确定性的，我们的设计上应该选择合理的突破这些限制。

PoW的绝对确定性机制应该包含下列要点：

稳定共识范围的建立

如前文所述，绝对最终确定性的本质要求是需要一个稳定共识范围，那如何引入，是直接改造PoW里那个不稳定共识范围，合二为一，还是额外引入一个新的，二者并列运行？

稳定共识范围对PoW的去中心化特性的影响有多大，会不会太削弱算力的权力，从而让这种PoW实际退化成一个投票机制？

确定性建立的时机

我们是要和一致性同时建立，还是可以分开？如果分开，确定性要延迟多久？理论上延迟要越小，就越需要那个建立一致性的不稳定共识范围（算力）服从于那个建立确定性的稳定共识范围，如何权衡？

稳定性共识范围如何做到激励相容

稳定性共识范围是某种机制选出来的，比如Staking，如果说对确定性进行投票决定了链的走向的话，投票人可以选择两边都投而没有任何损失，这就是无利害攻击（Nothing at stake），如何通过激励机制避免这种问题？

失败治理机制

确定性的建立，是通过牺牲活性换取了强一致性，那么就一定会遇到确定性的共识达不成的情况，这种情况好处是正好对外体现出了负责任的一面，达不成确定性，被确定的块的高度就不再增长了，链下活动也可以据此暂停，坏处是需要一套治理机制解决共识失败的情况。

对多链分片的支持

链外应用需要安全的获取的确定性信息，常规的方式是运行全节点，同步确定性共识结果并做验证，对于多链分片这种场景，每个分片一般是运行当前分片的全节点，运行其他所有分片的轻节点，这就涉及到一个问题，能否实现一个轻节点能安全的同步确定性共识结果，这是实现多链分片的一个重要问题。

另外，如果一个分片的链发生了分叉，如何让其他分片统一识别哪个是原有链，哪个是分叉链，并保证统一只跟其中一个链交互。

YeeCo的CRFG（Conditional Reward Finality Gadgets）提出了一套在PoW共识上建立绝对确定性的方案，后续的文章会做出详细介绍。

以上为YeeCo开发者的思考，不知大家有何见解，欢迎参与讨论。

[Yee Project]

Yee Project

YeeWallet: new version will be available soon
YeeWallet asset change notice feature is optimized. The new version will be released soon.

Yee Application YeeCall: new versions are available
1. Support group ownership transfer
2. Support group ban
3. Bug fixes

📲Download the latest version of YeeCall to experience the new features:
Google Play: https://play.google.com/store/apps/details?id=com.yeecall.app
iOS App Store: https://itunes.apple.com/us/app/yeecall-hd-voice-video-call/id852211576

YeeChain

At present, Tetris of the consensus mechanism part has been accomplished, and the P2P network management and state machine data fast synchronization module code have been released at Github. After further digital proof and engineering verification, modules for extracting consensus information from state machine data will be released.

According to the current test data, 50 nodes can synchronize state machine data in seconds, and TPS reaches over 10,000. The virtual machine module of the smart contract part has been designed and entered the encoding phase, and the slice storage network ESDHT enters the late stage of encoding. The developers of the development platform DAPPStore has completed the prototype verification of the program running environment.

Yee Community

YeeCall x ABCC Campaign has ended and the rewards will be distributed soon
YeeCall x ABCC Campaign has ended on August 15th. The qualified YeeCall users who signed up for ABCC exchange through the event page will get a random airdrop of 1–100 AT and get another 100YEE+5AT reward if the user transferred at least 10USDT worth of coins to his/her ABCC account. The rewards will be distributed to the qualified YeeCall users’ ABCC accounts within 5 days after the end of the campaign. Stay tuned for upcoming events!

Yee News

YeeCall was invited to attend “IEEE HOTICN 2018 Blockchain Technology and Application Forum”

On August 14th, YeeCall was invited to participate in the “IEEE HOTICN 2018 Blockchain Technology and Application Forum”. YeeCall CTO Jiang Zhouping attended on behalf of the YeeCall team and delivered a keynote speech.

YeeCall CTO Jiang Zhouping believes that blockchain technology is creating a value Internet. At the application level, YeeCall hopes to become the super entry of the blockchain through its super group that can host 50,000 members and newbie-friendly crypto wallet. At the technical level, YeeCall is building a new Tetris consensus mechanism and gradually realizing the layout of “private chain — alliance chain — public chain”.

Jiang Zhouping also participated in the roundtable forum and analyzed the blockchain technology and application in the coming year. The Institute of Electrical and Electronic Engineers (IEEE) is the world’s largest non-profit professional organization for the advancement of technology. It has more than 400,000 members in more than 160 countries. To date, IEEE has developed more than 900 industry standards in space, computing, telecommunications, biomedical, power and consumer electronics.

Yee and IBM Hyperledger held a meeting to discuss the development of alliance chain

On August 17, IBM technical experts and the head of the Hyperledger community visited the Yee Shenzhen R&D Center to discuss blockchain, alliance chain development and community building. Yee team said that at the end of September Yee public chain will build a developer community for the developers to build the YEE public chain together, and will contribute code to the Hyperledger developer community to jointly promote the development of blockchain technology. At the same time, Yee team invited Hyperledger to build a developer community at YeeCall.

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[Yee Project]

📲Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.

Yee Project

YeeWallet: new features will be available this week

1. support 0-conf transaction on BTC and BCH transfer (the detailed transferring process is displayed as soon as the transfer operation is confirmed)
2. BCH and ETH are added as anchoring cryptocurrency
3. Support BCH CashAddr

5 more popular coins are selected to be listed on YeeWallet. YeeWallet aims to be a crypto wallet that supports all of the popular coins. More popular coins will be added to YeeWallet.

Yee Application YeeCall: new versions are available

1. Support group ownership transfer
2. Support group ban
3. Bug fixes

📲Download the latest version of YeeCall to experience the new features:
Google Play: https://play.google.com/store/apps/details?id=com.yeecall.app
iOS App Store: https://itunes.apple.com/us/app/yeecall-hd-voice-video-call/id852211576

Yee Community

[COS Airdrop] Contentos x Yee 1 Million COS Airdrop has ended

On August 6, Yee joined with Contentos to airdrop 1 million COS to YeeWallet users. The airdrop has been distributed to the qualified users’ YeeWallet. More airdrops and events are coming. Stay tuned!
Visit Contentos official website to learn more about the project: www.contentos.io

Transfer contract service fee has been fully returned

The transfer contract service fee generated until the end of Sunday has been fully returned to the service users! For the relevant users, please check your YeeWallet. If you haven’t used the transfer contract yet, try it and experience the safe and reliable transaction. Download YeeCall to experience transfer contract now.

YeeCall x ABCC Campaign: Sign up to Get Double Rewards

YeeCall joins with ABCC to airdrop double rewards to YeeCall users.
Event time: 2018/8/1–2018/8/15
Sign up now: https://jinshuju.net/f/PUiMHM

How to join:
1. The YeeCall users who sign up for ABCC exchange through the event page will get a random airdrop of 1–100 AT, which means you can get at least 1 AT airdrop and the luckiest ones can even get a 100AT airdrop.
2. Transfer at least 10USDT worth of coins to your ABCC account, and you can get another 100YEE+5AT reward.
3. The snapshot of the event participants’ ABCC accounts will be taken at 23:59:59 August 15. AT will be airdropped to qualified users’ ABCC account. )
4. Rewards will be distributed to the qualified users’ ABCC accounts within 5 days after the event ends.
5. The users whose malicious or cheating behaviors are detected will be disqualified from the rewards.
Click to sign up: https://jinshuju.net/f/PUiMHM

Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:

Our website: www.yeefoundation.com
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[Yee Project]

📲Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.

Yee Project

YeeWallet: deposit with 0-conf transaction feature will be available this week; 5 more popular coins are listed on YeeWallet

YeeWallet’s 0-conf transaction feature will be available this week. With this feature, the deposit process (processing block) will be displayed as soon as the deposit operation is acquired. This will relieve the users’ anxiety while they are waiting for the deposit to be completed. The new version will also support BCH CashAddr format.

5 more popular coins are selected to be listed on YeeWallet. YeeWallet aims to be a crypto wallet that supports all of the popular coins. More popular coins will be added to YeeWallet.

Yee Community

YeeCall x ABCC Campaign: Sign up to Get Double Rewards

YeeCall joins with ABCC to airdrop double rewards to YeeCall users.
Event time: 2018/8/1–2018/8/15
Sign up now: https://jinshuju.net/f/PUiMHM

How to join:
1. The YeeCall users who sign up for ABCC exchange through the event pagewill get a random airdrop of 1–100 AT, which means you can get at least 1 AT airdrop and the luckiest ones can even get a 100AT airdrop.
2. Transfer at least 10USDT worth of coins to your ABCC account, and you canget another 100YEE+5AT reward.
3. The snapshot of the event participants’ ABCC accounts will be taken at 23:59:59 August 15. AT will be airdropped to qualified users’ ABCC account. )
4. Rewards will be distributed to the qualified users’ ABCC accounts within 5 days after the event ends.
5. The users whose malicious or cheating behaviors are detected will be disqualified from the rewards.

Click to sign up: https://jinshuju.net/f/PUiMHM

[COS Airdrop] Contentos x Yee 1 Million COS Airdrop

Yee has established a strategic partnership with Contentos, a globally-leading content public blockchain and a decentralizing global content eco-system. To celebrate the cooperation of the two parties, Contentos joins with Yee to airdrop 1 million COS to YeeWallet users.

Yee will take snapshots of YeeWallet users’ wallet accounts, and the users that meet the conditions will get COS airdrop.
The airdrop rules are as follows:
1. Snapshot period: 2018/07/08–2018/08/08 23:59:59 (GMT+8)
2. The users should meet 2 conditions:
a. have activated YeeWallet
b. hold average 500 or 500+ YEE in the YeeWallet in the past 30 days
3. The users that meet the conditions will share 1 million COS according to the proportion of the total YEE held by the qualified users that the average YEE you are holding in the past 30 days accounts for.
Eg., if the average YEE you are holding in the past 30 days accounts for 10% of the total YEE held by the qualified users, then you get 10% of 1 million COS.

Get more details: https://medium.com/@yeefoundation/cos-airdrop-contentos-x-yee-1-million-cos-airdrop-b1c4afea04da

Yee News

Yee application YeeCall is nominated for “2018 Chinese Excellent Technology Innovation Award”

YeeCall team’s innovation, a method and device for quickly calibrating video region of interest, is recommended by Chinese Scientists Forum and is nominated for “2018 Chinese Excellent Technology Innovation Award”. The Chinese Scientists Forum was founded by the famous scientist, former vice chairman of the Standing Committee of the National People’s Congress and Chairman of the Chinese Association for Science and Technology, Zhou Guangzhao.

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Join Yee official group in YeeCall to get free YEE giveaway http://doodle.yeecall.com/shares/invites?id=5af268a3e4b06b95d25db901
Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:
Our website: www.yeefoundation.com
Facebook: https://www.facebook.com/YeeToken/
Telegram: https://t.me/yeeofficialgroup

[Yee Project]

📲Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.

Yee Project

YeeWallet: transfer contract feature will be available by this weekend
YeeWallet team has completed the testing and optimization of transfer contract feature. The new version has been launched and under review and will be available by this week. With the transfer contract feature, the transaction and transfer between YeeCall users will be protected by the contract both parties made, thus safeguarding the interest of YeeCall users.

Yee Application YeeCall: new versions are available
1. Double click “YeeCall” at the bottom of the main interface to locate unread messages quickly.
2. Bug fixes

📲Download the latest version of YeeCall to experience the new features:
Google Play: https://play.google.com/store/apps/details?id=com.yeecall.app
iOS App Store: https://itunes.apple.com/us/app/yeecall-hd-voice-video-call/id852211576

Yee Community

2018 World Cup Guess Game has ended; check out the interesting numbers of the guess game
With the end of 2018 World Cup, our World Cup guess game has also ended. Did you guess the Champion correctly? How many bets did you win? Are you the best predictor? Let’s check out some interesting numbers of the guess game.

The Biggest Winner
The YeeCall player that won 20062.74509347 YEE throughout the game

The Biggest Loser
The YeeCall player that lost 5080 YEE throughout the game

The Best Predictor
The YeeCall player that guessed 42 match results correctly

The Unluckiest Player
The YeeCall player that guessed wrong on 39 match results

The Luckiest Player
The YeeCall player that guessed right on 10 match results consecutively

The Most Unexpected Match Winner
Mexico in Mexico vs. Germany, the reward is 40 times of the bet amount

The Most Profitable Match
Croatia vs. England, the players that guessed right won 1875.62919463YEE

Yee News

SouthEast’s largest technology media e27 published a news report on YeeCall’s strategic financing and YeeCall’s plan on developing various blockchain solutions

On July 5, YeeCall announced that it has raised US$5 million in a strategic financing round, led by Leo Digital Network, a subsidiary of Shanghai-based Leo Group.

SouthEast’s largest technology media e27 published a news report on YeeCall’s strategic financing and that “YeeCall will use the capital to set up a blockchain industry solution business unit, and launch new industrial solutions on blockchain”.

Check out the news: https://e27.co/video-conference-calling-app-yeecall-raises-us5m-venture-blockchain-20180718/

Follow us on Twitter to get the latest updates: https://twitter.com/YeeToken
Join Yee official group in YeeCall to get free YEE giveaway http://doodle.yeecall.com/shares/invites?id=5af268a3e4b06b95d25db901
Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:
Our website: www.yeefoundation.com
Facebook: https://www.facebook.com/YeeToken/
Telegram: https://t.me/yeeofficialgroup

[Yee Project]

📲Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.

Yee Project

YeeWallet: recharge with 0 confirmation feature is under developing

This week, YeeWallet is developing a feature that will enable YeeWallet to support recharge with 0 confirmation. With this feature, the recharge process (processing block) will be displayed as soon as the recharge operation is acquired. This will relieve the users’ anxiety while they are waiting for the recharge to be completed.
The new version will also support the new CashAddr Bitcoin Cash address format.

Yee Application YeeCall: new versions are available

1. Support scanning QR code to add friend, join group, and follow channels
2. Support identifying the QR code in a picture
3. Bug fixes

📲Download the latest version of YeeCall to experience the new features:
Google Play: https://play.google.com/store/apps/details?id=com.yeecall.app
iOS App Store: https://itunes.apple.com/us/app/yeecall-hd-voice-video-call/id852211576

Yee Community

With the help from Yee community, YEE token successfully got listed on FCoin Exchange

Thanks to the support and help from Yee community, YEE successfully got listed on FCoin exchange. Though the listing time is postponed to July 4th due to the traffic congestion, that is another great accomplishment that Yee team and Yee community achieved together. Good job, Yee community!

YeeCall referral campaign ‘Invite Friends & Win Up To 30,000 YEE’ has ended

YeeCall referral campaign has ended on June 30. By referring friends to download and sign up for YeeCall, both the attendee and the friend can get 100YEE rewards. The maximum YEE every attendee could get is 30,000. The reward will be distributed within 15 days after the event is over. Stay tuned for the upcoming events!

The playing method of World Cup match result guess game is changed, MORE EXCITING!

The 2018 World Cup has come to the knockout phase. To make the match result guess game more exciting, our team has changed the playing method of the game. Rather than betting 10YEE on each guess, the players can choose the amount of YEE tokens that want to bet, from 10YEE to 500YEE. Enjoy the game!

Join the game and discuss with global players: http://doodle.yeecall.com/shares/invites?id=5b3606f6e4b086f7adf0c262

Yee News

YeeCall has finished B1 strategic financing and will explore the application of blockchain technology in industries

On July 5, “YeeCall Strategic Financing Press Conference” was held at Crowne Plaza, Beijing. Over 10 renowned VCs and PE investors, 5 financial institutions, and 30 media partners attended the conference. At the conference, Yee CEO Zhang Lei announced that YeeCall has received millions of dollars strategic investment.

Zhang Lei also announced that YeeCall will set up a Blockchain Industry Solution BusinessUnit and explore the application of blockchain technology in Industries.

Follow us on Twitter to get the latest updates: https://twitter.com/YeeToken

Join Yee official group in YeeCall to get free YEE giveaway http://doodle.yeecall.com/shares/invites?id=5af268a3e4b06b95d25db901

Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:

Our website: www.yeefoundation.com

Facebook: https://www.facebook.com/YeeToken/

[Yee Project]

📲Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.

Yee Project

YeeWallet: contracting transfer feature is under beta testing

The contracting transfer feature is under beta testing. With this feature, the transaction and transfer between YeeCall users will be protected by the contract both parties made, thus safeguarding the interest of YeeCall users.

Yee Application YeeCall: the new features of ‘scan QR code’ and ‘create group face to face’ is under beta testing

1. ‘scan QR code’ feature is under beta testing. this feature provides a new way to add a friend or join a group.
2. ‘create group face to face’ feature is under beta testing. It is an interesting way to create a group with your friends.

📲Download the latest version of YeeCall to experience the brand new interface:
Google Play: https://play.google.com/store/apps/details?id=com.yeecall.app
iOS App Store: https://itunes.apple.com/us/app/yeecall-hd-voice-video-call/id852211576

Yee Community

YeeCall referral campaign ‘Invite Friends & Win Up To 30,000 YEE’ is still going on

YeeCall referral campaign has officially started on June 25. By referring your friend to download and sign up for YeeCall, both you and your friend can get 100YEE rewards. The maximum YEE every attendee could get is 30,000.

Event ends on 6/30 23:59:59 (UTC+8)
Rewards will be distributed within 15 days after the event is over.
Download YeeCall to get 100YEE right away:https://ws92t.app.goo.gl/E6ap

Don’t miss the chance to win 30,000 YEE! All you need to do is tap the referral button!

The playing method of World Cup match result guess game is changed, MORE EXCITING!

The 2018 World Cup has come to the knockout phase. To make the match result guess game more exciting, our team has changed the playing method of the game. Rather than betting 10YEE on each guess, the players can choose the amount of YEE tokens that want to bet, from 10YEE to 500YEE. Enjoy the game!

Join the game and discuss with global players: http://doodle.yeecall.com/shares/invites?id=5b3606f6e4b086f7adf0c262

Yee News

YeeCall is recommended as an excellent app by OPPO App Store and included in the Editor’s Choice list

Due to its superb user experience and self-developed communication technology, YeeCall is recommended by OPPO App Store as an excellent app and included in the Editor’s Choice list.

Yee CEO Zhang Lei was invested to attend “To See the Future” World Blockchain Conference

On June 29, Yee CEO Zhang Lei was invested to attend “To See the Future” World Blockchain Conference and gave a speech “YeeCall, the Infrastructure of the Blockchain Era”.

Yee CEO Zhang Lei was invested to be one of the advisors of ABCC exchange

Yee CEO Zhang Lei was invested to be one of the advisors of ABCC exchange. ABCC is a world-class cryptocurrency exchange that aims to provide a frictionless, user-centric trading experience. It was founded by Calvin Cheng, a technology and media magnate, and other co-founders with a broad range of experience and track record at some of the most successful Internet, financial services and management consulting firms.

Follow us on Twitter to get the latest updates: https://twitter.com/YeeToken
Join Yee official group in YeeCall to get free YEE giveaway http://doodle.yeecall.com/shares/invites?id=5af268a3e4b06b95d25db901
Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:
Our website: www.yeefoundation.com
Facebook: https://www.facebook.com/YeeToken/
Telegram: https://t.me/yeeofficialgroup

[【邀好友赢YEE币】第二期活动开始啦~ 邀请者和受邀人都有奖，且奖励更加丰厚， 最高可得30000YEE！]

【邀好友赢YEE币】第二期活动开始啦~ 邀请者和受邀人都有奖，且奖励更加丰厚， 最高可得30000YEE！

【邀好友赢YEE币】第二期活动已于6月25日正式启动！只要在活动期间邀请好友成功下载注册YeeCall，你和你的好友都可赢得100YEE币奖励。多邀多得，最高可赢取30000YEE币奖励！你还在等什么，赶快邀请小伙伴一起赢YEE币吧~

参与YeeCall世界杯竞猜，瓜分百万YEE币大奖！

通过此链接注册下载YeeCall,领取100YEE：http://sl.yeecall.cn/jIzq2a

[Yee Project]

📲Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.

Yee Project

YeeWallet: coin price trend chart will be available this week and email verification feature will be launched next week

YeeWallet team is currently developing new features such coin price trend chart and email verification to improve user experience and strengthen the security of YeeWallet users’ asset. The new features will be available soon. Stay tuned.

Yee Application YeeCall: the new version will be available this week

YeeCall’s new version will be released this week. What’s new with the new version:

1. the user should get the admin’s permission to join a group.
2. the user can choose to join a group or not rather than being added directly by his/her contacts.
3. forbid the group members to add someone through the group.
4. bug fixes.

📲Download to experience the latest version of Yee application YeeCall with YeeWallet integrated’:

Google Play: https://play.google.com/store/apps/details?id=com.yeecall.app

iOS App Store: https://itunes.apple.com/us/app/yeecall-hd-voice-video-call/id852211576

Yee Community

Yee x DEx.top 1,000,000 YEE Giveaway has began

Yee and DEx.top have established a strategic partnership and will carry out in-depth cooperation in community development, inclusive finance, and more fields.

To celebrate YEE being listed on DEx.top, Yee joins with DEx.top to hold a 1,000,000 YEE giveaway activity for YEE token holders from June 1, 2018 13:00 to June 6, 2018 13:00(HKT). With this activity, you can:

1. Enjoy 0 trading fee when you trade on DEx.top during its public beta period.
2. Share 800,000 YEE by joining YEE trading competition and ranking TOP20.
3. Receive 900 YEE tokens (first come first serve) when your trading volume (buy+sell, wash trading not included) is over 0.1 ETH.
4. Join DEx.top’s Official YeeCall Group, and share a total of 20,000 YEE airdrops everyday during the event period.

Check out more details: https://dextop.zendesk.com/hc/en-us/articles/360005142894

Join DEx.top’s Official YeeCall Group: http://doodle.yeecall.com/shares/invite?id=5b0e3a36e4b032f3043f855c

Yee x CoinTiger YEE Trading Competition has ended

On May 24, CoinTiger launched YEE/BTC and YEE/ETH trading pairs and joined Yee to hold “2,000,000 YEE reward for YEE trading competition” activity. The users whose YEE accumulated trading volume (buying volume + selling volume without executed volume by your own) ranks top 100 (minimum trading volume should be more than 10,000 YEE) will share a prize pool of 2,000,000 YEE. The competition has ended and the reward will be distributed to the qualified users in five working days.

Yee News

Yee CEO Zhang Lei: “To apply the blockchain technology, you have to solve 3 problems.”

Yee CEO Zhang Lei was interviewed by AiNotesman, a popular technical self-media in China. In the interview, Zhang Lei shared his thoughts on the blockchain technology, including what blockchain is and the three key points of blockchain. He pointed out that to apply the blockchain technology, the team should solve 3 problems, and they are computing, storage, and bandwidth problems. He also shared that Yee team will work with companies in other industries, such as shared ride, to build alliance chains.

Check out the whole interview here: https://mp.weixin.qq.com/s/n5ny5V8vlDqX-uxibyqBtA

Follow us on Twitter to get the latest updates: https://twitter.com/YeeToken

Join Yee official group in YeeCall to get free YEE giveaway http://doodle.yeecall.com/shares/invites?id=5af268a3e4b06b95d25db901

Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:

Our website: www.yeefoundation.com

Facebook: https://www.facebook.com/YeeToken/

Medium: https://medium.com/@yeefoundation/

Telegram: https://t.me/yeeofficialgroup

Reddit: https://www.reddit.com/user/yeetoken

Steemit: https://steemit.com/@yeefoundation

[一、交易排名赛：80万YEE大奖等你拿]

近日，YeeCall团队与比特大陆孵化的去中心化交易所DEx.top达成战略合作，将在社群发展、普惠金融等方面进行深度合作。
DEx.top作为去中心化交易平台，具有交易资产安全可靠、瞬时交易确认、更低的Gas消耗等特点。

YeeCall与DEx.top联合活动为YeeCall小伙伴们带来四重福利。

DEx.top官方YeeCall群：http://doodle.yeecall.com/shares/invite?id=5b0f91c7e4b019f53adeed8c

一、交易排名赛：80万YEE大奖等你拿

活动时间：（新加坡时间）2018年6月1日13:00－6月6日13:00
活动期间，YEE累计交易量（买入+卖出且不含自成交）大于0.5 ETH，交易量排名前二十的用户瓜分800,000 YEE



二、参与交易每人领取900YEE空投奖励

活动期间，参与YEE交易，凡是累计交易量（买入+卖出且不含自成交）大于0.1ETH的用户，均可领取900YEE奖励（先到先得），180,000 YEE送完为止。

三、加入DEx.top官方YeeCall群，20,000YEE红包天天领！

活动期间，加入DEx.top官方YeeCall群，群内每晚20:00（HKT）发放YEE红包，20,000YEE发完为止！
官方群：http://doodle.yeecall.com/shares/invites?id=5b0e3a36e4b032f3043f855c

四、公测期间DEx.top交易0手续费

更多详情：https://dextop.zendesk.com/hc/zh-cn/articles/360005142894

On May 24-25, Blockchain Festival hosted by Huobi Pro will be held in Ho Chi Minh City, Vietnam. Yee team as one of the sponsors will go to the festival, and YeeCall COO Ruan Long will be attending Blockchain Festival as a Panel Speaker and discuss the topic: The New Era of Blockchain Starts Here.

Yee team will also take this opportunity to hold a community meet-up in Vietnam, and it will be the first overseas meet-up of Yee community. Although the event location and time are not confirmed yet, what is confirmed is that we’ll bring a lot of benefits and surprises to the attendees. In addition to that, the team will give away 2 Blockchain Festival tickets ($35/ticket) to invite you to join us at the festival. If you are in Vietnam, this is something you definitely don't want to miss.

Join Yee Vietnam Group to learn more: http://doodle.yeecall.com/shares/invites?id=5afcf5d3e4b0c3ac9fd7d25b

See you!

2018年5月24日至25日， “Blockchain Festival”行业峰会将在越南胡志明市隆重举行。本次会议由火币主办，Yee作为赞助商之一将出席会议，YeeCall COO 阮龙也将作为发言者就“区块链的新时代从这里开始”这一议题发表讲话。

Yee团队借此机会将在越南举办一场线下见面会，具体日期和地点未定，可以确定的是作为Yee社群的首次海外线下见面会，丰厚的福利必不可少，团队还会赠送两张价值222元的区块链峰会门票，在越南的YeeCall小伙伴一定不能错过！

加入我们的越南社群，了解更多详情 http://doodle.yeecall.com/shares/invites?id=5afcf5d3e4b0c3ac9fd7d25b

期待与你相会！

[To promote the joint development of BCH and Yee community, Yee and BCF have established a strategic partnership and decided to airdrop 20 BCH to YeeCall users.]

To promote the joint development of BCH and Yee community, Yee and BCF have established a strategic partnership and decided to airdrop 20 BCH to YeeCall users.

The Bitcoin Cash Fund (BCF) is a passionate group of professionals committed to the long-term success of BCH. YeeCall, an IM and the first application of Yee project, has 33 million users worldwide. With this large user base and its own cyptocurrency wallet, YeeWallet, built in, Yee believes that the support of BCH on YeeWallet will not only enrich the YeeCall’s application scenario and satisfy YeeCall users’ needs but also extend the BCH’s influence and promote the development of BCH community.

In the light of this agreement, BCF joins with Yee to airdrop 10 BCH to YeeCall users. The users who hold 10,000 or 10,000+ YEE in YeeWallet will share 20 BCH.

Yee will take snapshots of YeeCall users’ wallet account, and the users that meet the conditions will get BCH airdrop.

The airdrop rules are as follows:

1. Snapshot time: 2018/05/09 23:59:59 (GMT+8)

2. The users should meet 2 conditions:

a. have activated YeeWallet

b. hold 10,000 or 10,000+ YEE in YeeWallet

3. The users that meet the conditions will share 20 BCH according to the percentage of the total YEE held by the qualified users that your YEE accounts for. Eg., if the number of YEE in your YeeWallet accounts for 10% of the total YEE held by the qualified users, then you get 10% of 20 BCH.

4. The qualified users will get BCH airdrop within 24 hours after snapshots are taken.

What is snapshot?

Snapshot is a way of automatically recording the total asset in a YeeWallet account at a certain time, which means users don’t need to do anything.

What is BCH?

Bitcoin Cash (BCH) is a legendary crypto currency. It is an upgraded version of the Bitcoin Core software. It was released on August 1st, 2017. The main upgrade offered by Bitcoin Cash is an increase of the blocksize limit to 8mb. This effectively allow miners on the BCH chain to process more payments per second. This makes for faster, cheaper transactions and a much smoother user experience.

Bitcoin Cash Fund (BCF) is a passionate group of professionals committed to the long-term success of this legendary crypto currency. Their fund is donated by individuals or sponsored by enterprises. BCF will allocate the fund to the promissing projects that has great influence to promote BCH community.

BCF has 3 board members:

IAN DESCÔTEAUX, entered the Bitcoin space in 2010 and built up a mining farm and has been mining ever since.

Paul Wasensteiner, entered the Bitcoin space in 2011, and founded the Bitcoin Cash Fund in November 2017.

Haipo YANG, founded the highly successful mining pool ViaBTC, and led the R&D team at ZeusMiner.

___________________________________________________________________________

Follow us on Twitter to get the latest updates: https://twitter.com/YeeToken

Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:

Our website: www.yeefoundation.com

Facebook: https://www.facebook.com/YeeToken/

Telegram: https://t.me/yeeofficialgroup

Reddit: https://www.reddit.com/user/yeetoken

Steemit: https://steemit.com/@yeefoundation

Bitcointalk: https://bitcointalk.org/index.php?topic=2714537

近来，BEC、SMT的智能合约漏洞给很多区块链从业者带来了恐慌。我们先来看看案发现场：

上图，利用BEC漏洞创造出巨额token

上图，利用SMT漏洞创造出巨额token

YEE区块链团队第一时间查阅了BEC、SMT的代码，BEC的合约漏洞是BatchTransfer漏洞中的数据溢出，SMT的合约漏洞是代理转账逻辑中没有进行大数保护，造成大数溢出，这两个问题的根本原因是没有使用library SafeMath，使用了普通的加减乘除。

比如BEC漏洞中这个乘法没有使用library SafeMath，而是用了“*”，这就造成了数据溢出。



同样道理，SMT的智能合约的错误代码没有使用官方的library SafeMath，而使用了普通的“+”，这造成了在代理转账逻辑中没有进行大数保护，最终造成大数溢出。



正确的方式应该像我们的这段代码就是用library SafeMath函数来完成智能合约代码，这样可以保证智能合约代码的安全稳定。



现在发现的漏洞中有很多代码是因为直接使用普通的加减乘除，同时缺少溢出判断，这就造成数据溢出的隐患，而使用library SafeMath可以彻底解决数据溢出的问题。因此，解决方案也很简单，彻查智能合约代码，把“+”“-”“*”“/”换成library SafeMath，这可以彻底解决数据溢出的问题。

YEE也在这里希望所有区块链从业者在关注出席会议、媒体曝光的同时，应将更多注意力关注到技术层面，只有安全的技术才能保障区块链产品的正常运行，让更多人享受到区块链带来的各种服务。

YEE落地产品YeeCall这个产品本身就面临着巨大的技术挑战，我们在全球布网，从零建设起了一张拥有5个数据中心、400多个中继节点的覆盖全球的通讯网络，这张网络一度被AWS、澳洲电信称之为全球通讯网络的“最后一公里”。为了解决手机端通讯的复杂环境和超多终端支持问题，我们除了一行一行代码敲出了完全拥有自主知识产权的通讯协议，还创造性采用人工智能的方法来解决噪音消除问题，所有这一切，都是为了让广大的YeeCall用户体验更好，与家人和朋友的沟通更紧密。

我们热爱技术，拥抱区块链，也欢迎Java、服务器、Android、iOS、区块链技术方面的有识之士加入YEE团队，共同打造区块链的美好未来，邮箱：dream@yeecall.com

Recently, the exposure of BEC and SMT’s smart contract security loopholes has panicked a lot of blockchain practitioners. Let's have a look at the "crime scene" first.

Using the BEC loophole to create a huge amount of tokens

Using the SMT loophole to create a huge amount of tokens

Upon the exposure, Yee team checked BEC and SMT’s smart contract code immediately, and found out that BEC’s smart contract security loophole is due to the data overflow of BatchTransfer loophole, and SMT’s smart contract security loophole is caused because there is no protection for large numbers in the proxy transfer logic, resulting in the overflow of large numbers. The root cause of these two problems is that library SafeMath is not used, and ordinary addition, subtraction, multiplication and division are used.

For example, in the BEC loophole, this multiplication does not use library SafeMath. Instead, it uses "*", which causes data overflow.



By the same token, the error code of SMT's smart contract does not use the official library SafeMath, but uses the ordinary "+" instead, which leads to large numbers lacking protections in the proxy transfer logic, resulting in the overflow of large numbers.



The correct way is to use the library SafeMath function as our code does to complete the smart contract code, which can ensure the security and stability of the smart contract code.



Currently, many of the exposed loopholes are due to the direct use of ordinary addition, subtraction, multiplication, and division, and lack of overflow judgment, which poses the data overflow risk. However, the use of library SafeMath can completely solve the problem of data overflow. Hence, the solution is simple: look through the smart contract code, and replace "+" "-" "*" "/" with library SafeMath. This can completely solve the problem of data overflow.

Here, Yee also hopes that all blockchain practitioners could pay more attention to the technical level while attending meetings and enhancing media exposure. Only safe technologies can guarantee the normal operation of blockchain products and enable more people to Enjoy the various services brought by the blockchain.

Yee application YeeCall itself faces enormous technical challenges. We have built a global communications network with 5 data centers and more than 400 relay nodes, and this network is once called by AWS and Telstra as the "Last Mile" of the global communications network. In order to solve the complex environment and ultra multi-terminal support problems in mobile-end communications, our technical team keep coding days and nights and managed to develop a communication protocol that completely possesses independent intellectual property rights, and we also creatively used artificial intelligence to solve the noise elimination problem. All of these are serving the same goal: to make YeeCall users have a better user experience and communicate more closely with family and friends.

We love technology and embrace the blockchain. We also welcome talents in Java, server, Android, iOS, and blockchain technology fields to join the Yee team and create a better future for the blockchain. If you’re interest in joining us, please contact us at: dream@yeecall.com

[互联网的超级入口是微信]

在过去的两年，YeeCall专注提供高品质的通讯和内容消费体验，在全球获得了3000多万用户的热爱，也得到了众多投资人的鼎力支持。区块链时代，我们认为有非常大的机会将经济价值同化到社交体系中。最新版的YeeCall集成了IM+数字钱包，用户可以与5万人在线群聊，也可以随时发送数字资产红包。在不远的将来，我们希望成为“区块链的超级入口”，通过“超级社群”、“超级钱包”、“DApp Store”为区块链用户提供一站式服务。

互联网的超级入口是微信

移动互联网时代，即时通讯 IM已经成为用户和流量的超级入口，WhatsApp、Facebook Message、Line、Wechat等拥有了大量的用户、高频的使用、以及超长的用户时长。

在中国，微信进一步成为一个生态系统，引领了一个新的移动经济时代：将经济价值同化到通信系统中。聊天、社交媒体和在线支付等数字服务已经开始在日常生活中发挥重要作用。消息系统承载了人们的关系网络、日常沟通以及信息获取；移动支付的飞速发展，已经让服务、商品的获取与交易变得与聊天一样方便。微信等通信系统集成了商品交易、线下服务，甚至理财与保险等金融服务，已经日益成为现代社会的重要基础设施。

区块链创造新一代入口的机会

区块链是新一代协议。如果说TCP/IP协议的诞生创造了以信息流动为中心的互联网，那么以区块链为代表的信用协议（Trust Protocol）正在缔造一个以价值流动为中心的价值互联网，我称之为“互信网”。

区块链是一次技术革命，它真正创造了一种不可更改、不可摧毁的分布式数据库技术，只具备写和读两种功能，不能更新，也不能删除，这对很多系统的设计都是一种颠覆。Token实现了商业逻辑再造，它让价值有了明确的技术定义，重构了价值流动网络。这也创造了一种新型组织形式——去中心化自治组织（Decentralized Autonomous Organization ，简称DAO），它是一次组织革命，改变了原有的生产关系。

可以说，区块链技术不仅改变了价值存储方式，还重新定义了价值流转的方式，甚至颠覆了原有生产关系，从而构建了一个可以让价值自由流通的传输网络，可以称之为价值互联网。因此，价值在这样一个全新网络上传输具备三个特质：

1. 区块链技术
底层架构运用区块链技术，保障安全、便捷的价值传输

2. 价值容器
具备一个价值容器，可以储存价值，并在一定程度上助力价值的流通

3. 协作组织
具备一个支持区块链生产关系组织结构的平台，它不仅能实现人与人的协作，还要实现人与组织、组织与组织的协作，更需要实现人与物、物与物的协作，这就是物联网的范畴

这也是YeeCall的努力方向，我们希望运用区块链技术，集成钱包和社群的功能，打造成为“区块链的超级入口”，让小白也能使用区块链服务，享受到区块链带来的红利。

超级社群、超级钱包、DApp Store将构成区块链的超级入口

创立伊始，YeeCall就在使用分布式传输技术实现点对点、群组的通讯，目前，YeeCall建立了一张覆盖全球227个国家、1000多家运营商的通讯网络，拥有5个数据中心、400多个中继节点，70%的流量通过分布式模式传输。

超级社群将成为区块链时代的协作组织

社群会是区块链时代组织结构的主要形态，人与人、人与组织、组织与组织、人与物、物与物等每一个商业角色间的协作都将通过社群来完成。社群将以自组织形态来呈现，每一个商业角色都可以组建属于自己的“超级社群”。如果说微信创造了自媒体，彻底解放了媒体的生产力，那么YeeCall认为，社群将解放传统组织的生产力，让商业角色间的协作更便捷、更迅速。

社群创建者会成为这个社群的核心，他既是社群的运营者，又可以通过社群获得价值，这个价值不仅局限于情感层面（结识朋友），还可以通过发布更优质内容、建立更深厚的关系，持续提升社群的价值，获得激励。为此，YeeCall会提供一系列工具帮助社群运营者，目前YeeCall群聊上限增至最多5万人，全面支持文字、图片、语音、视频以及各类文件等消息类型，后续版本将上线群发现功能，越优质的群越可能获得更多粉丝关注。未来还会上线feed流、自定义插件、消息打赏等功能，切实帮助社群创建者提升运营效率，获取更大的收益。

超级钱包将成为价值容器

YeeCall新上线的钱包功能定位于一站式数字资产管理服务平台，目前支持ERC20的数字资产，未来将支持Bitcoin、Ethereum、Ripple、Bitcoin Cash、Litcoin、EOS、Stellar、Cardano、NEO、IOTA等数字资产。

YeeCall将数字资产定义为零钱、卡、投资账号三个部分。“零钱”是一个高频使用场景，社群沟通、社群激励以及点对点的沟通和激励都会使用，这一版YeeCall上线了钱包和红包功能，用户可以收到第一个数字资产红包，也可以像微信红包一样的发放区块链红包。“卡”对应的公链钱包，YeeCall将设计一系列措施保障资产安全，就像将数字资产装进一个自有的加密保险箱。“投资账号”就是交易所账号，可以进行数字资产托管。

DApp Store将成为更多区块链服务的入口

未来YeeCall还将上线DApp Store，它将成为应用场景的承载容器，用户可以像使用微信小程序一样，无需打开其他应用程序即可以享受到丰富的区块链服务。

在区块链时代，YeeCall的全球化经验将起到至关重要的作用。日本、韩国、东南亚、中东、印度在内的全球市场都将成为YeeCall的拓展方向，未来将根据地区发展制定不同的拓展策略，分阶段将区块链各种应用场景落地，特别是跨境转账这种刚需场景。

从接触区块链伊始，YeeCall就认为这是一个比肩互联网的巨大机遇，YeeCall自身的技术沉淀、产品规划以及过往经验将帮助YeeCall在最短时间内成长为“区块链的超级入口”。

[Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.]

Download the latest versions of YeeCall on Google Play & iOS App Store to experience YeeWallet features.

Join Yee official group in YeeCall and get free YEE giveaway http://doodle.yeecall.com/shares/invite?id=5ac4d19ae4b03a80d851c2be

To celebrate the launch of YeeWallet that is built in the latest versions of YeeCall, Yee holds another airdrop called ‘Invite Friends & Win YEE’ to thank Yee users’ support.

How to Play?

1. Download the latest version of YeeCall

Download to experience the latest version of YeeCall:
Google Play: https://play.google.com/store/apps/details?id=com.yeecall.app
iOS App Store: https://itunes.apple.com/us/app/yeecall-hd-voice-video-call/id852211576

2. Tap the ‘Get your first Bitcoin’ message to join the airdrop.

3. Tap the ‘Share my link & Win Bitcoin’ button.

4. Share the referral link to your friends through channels like Facebook, Twitter, Messenger, WhatsApp, WeChat, etc. and invite them to download and sign up with YeeCall (the friends you invited should be those who hasn’t downloaded and signed up with YeeCall). You’ll get 10YEE for each valid invitation, and get as much as 1,000 YEE which is about 1.5 milli-Bitcoins.

All done and you can just wait for the distribution of the rewards!

FAQ about ‘Invite Friends & Win YEE’

We encourage YeeCall users to invite friends into YeeCall. Regarding cheating and other behaviors that interfere other users’ normal use of YeeCall, we will take strict measures to ban or deal with them.

1. What is the ‘invite friends’ procedure?
Share the link to your friend; after your friend downloaded and signed up with YeeCall through the link you shared and registered at YeeCall, the ‘invite friends’ procedure is completed.

2. Is there a cap on the number of friends I invite?
There is no cap on this. However, one YeeCall user can get at most 1000YEE in this activity.

3. How to define a successful invitation?
After the invited friend registered at YeeCall, the invitation is recorded in our database and under review. After the activity ended, the verified invitation is confirmed as a successful invitation.

4. When does this activity end?
The first round of ‘Invite Friends to Win YEE’ will end on 4/15.

5. When will the rewards be distributed?
After the ‘Invite Friends to Win YEE’ activity ended, we’ll review the invitations. After the review is finished, we’ll distribute the rewards according to the number of valid invitations. We’ll take strict measures to deal with cheating behaviors and distribute the rewards after the citizen ID is verified.

6. How to check the received rewards?
It will take a certain amount of time before the tokens are credited into the account. We’ll distribute the rewards to your YeeWallet within 30 days after the event ended. By then, you can tap the discover tab, open YeeWallet, and tap YEE to check the transaction detail.

7. What will YEE be used for?
It will be the cryptocurrency circulating in the Yee ecosystem. In the future, it will be used in global transfers, instant messaging, content incentive and other application scenarios. YeeCall sincerely hope you can invite more friends into Yee ecosystem .

8. Can the friend that is successfully invited get rewards?
No, only the inviter can get the rewards.

Follow us on Twitter to get the latest updates: https://twitter.com/YeeToken

Join Yee official group in YeeCall and get free YEE giveaway http://doodle.yeecall.com/shares/invite?id=5ac4d19ae4b03a80d851c2be

Check out more details about Yee project, YeeCall, and YEE token at our website and other channels:

Our website: www.yeefoundation.com
Telegram: https://t.me/yeeofficialgroup
Medium: https://medium.com/@yeefoundation
Reddit: https://www.reddit.com/user/yeetoken
Steemit: https://steemit.com/@yeefoundation