Bitcredit/CRE,
first implementation of a "soft" sidechain,
fully claimable for all Bitcoin holders,
with a combined proof-of-work/proof-of-deposit mining system
Main features of Bitcredit- Implementation of a (for the moment) one way "soft" sidechain.
- Bitcredits are claimable from Bitcoin; up to 90% of the total Bitcoin monetary supply at any given time can be used to claim bitcredits. Bitcredit runs in parallel with Bitcoin and connects directly to the Bitcoin network, as well as running a separate network. This feature currently do not exist in any other system and will allow a migration path for any Bitcoin user. Bitcoins are NOT spent to claim Bitcredits; instead bitcoins will act as a ticket for claiming. Bitcredit will track the bitcoin network for the coming five years. This means that Bitcredit is effectively integrated with the Bitcoin mining system for the same period.
- Unique combined proof-of-work/proof-of-deposit mining algorithm. The pow/pod mining algorithm solves among other things one major problem with Bitcoin, namely the direct relation between inflation, Bitcoin value and mining costs. It can also be argued that it provides a higher level of security, where the system is dependent mostly on itself. In the absolute start-up phase, approximately the first six months, only proof-of-work mining will be possible and once initially mined coins will become available for deposit the system will gradually and automatically shift toward the combined pow/pod algorithm.
- Supply is released over an S-curved distribution plan. Early startup phase will have coins released at a slower rate and once adoption starts to pick up the rate will increase. Coins are released in relation to the total monetary supply, to compare with Bitcoin where the supply is released at a rate that is tied to the depth of block chain. This type of distribution puts emphasis on actual demand rather than focus on early adopters.
- Total monetary supply is 30 000 000 bitcredits. Half of the supply will be kept in deposit at any given point in time. This means that only 15 000 000 bitcredits will be available for spending, making the effective supply slightly less than the Bitcoin supply. Initial distribution is also faster, which means that 90 percent distribution will be achieved at about the same time as Bitcoin.
- The deposits for the proof-of-deposit system can be created offline, minimising the risk when participating in the mining system.
- Multiple parties can take part in a mining effort, with different roles for depositor and miner. Instead of contributing to mining pools this may instead cause the rise of deposit pools, shifting the focus of the mining process from mining power to deposit power.
- Claims can be generated offline, and in a way that guarantees the claiming party not to put their bitcoins at risk.
- The future possibility to use bitcredits as coloured coins has been taken into consideration when the protocol was created.
- Bitcredit has a higher block limit from the start, 4MB. Block limit will be increased in line with the planned Bitcoin block limit raise.
- Safer transfer of bitcredits ownership. Verification sign-off is built into the protocol to enable a receiver to verify that a transaction is correct before it gets finalised.
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How do I get started?Software and further information can be found at
http://bitcredit-currency.org.
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Why a new coin type?It can be argued that there are several drawbacks to a sole proof-of-work system. One is the relation between coin valuation and mining costs, where the mining cost effectively limits the total value of the system. In short, if a system has a ten percent inflation rate per year the cost of mining will gravitate towards ten percent of the whole value of the system. Or, looking from the other side, the total value of the system will gravitate towards the mining costs. With a system that mainly depends on entities proving that they have control over system assets, the direct connection between mining and price will be removed.
It is also quite difficult to measure the security in a proof-of-work system apart from being able to tell that the difficulty is at a certain level. Any entity can take part in mining and also without notice add a lot of resources in an attack, whereas a combined system that also requires resources internal to the system mitigates that type of attack. If the parties taking part in the mining system also are invested in the same system, the will act in self-interest to preserve the system. This type of self-enforcing behaviour has been discussed in Satoshis original white paper on Bitcoin.
Once a large enough blockchain has been established an external brute force attack done solely through mining power will not be possible.
Bitcoin also suffers from a problem with several unknowns with regards to a relative high number of coins in existence. There exists both so called zombie coins, coins that have not been touched in a long time, and a large amount of coins mined initially by Satoshi, the initial creator of Bitcoin. These two sets of coins have been estimated to be approximately 3 000 000 in total. This is not a problem in and by itself, but if and when any large amount of dormant coins starts to move, it can potentially cause problems, ranging from fear to price collapse. This may even be more true for the coins belonging to Satoshi himself, which have been estimated to be in the range of 1 000 000 coins. If a controlled migration path to a new system is offered, this will either force dormant coins to move, or prove that they are in fact stale.
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What are the main drawbacks of Bitcredit?- More moving parts means a more complex machine. The dependency on Bitcoin could potentially prove to be troublesome, this dependency will exist for approximately five years.
- If a fatal flaw occurs in Bitcoin it will (probably) also affect Bitcredit. The Bitcredit system is however not dependent on on-going mining in the Bitcoin blockchain.
- The dependency on the Bitcoin blockchain means that initial download is the download of the Bitcoin blockchain, plus the initial sync between the Bitcredit blockchain and the Bitcoin blockchain. This will naturally cause more overhead. Initial sync may take a lot of time. There are three distinct steps in the initial sync; the Bitcoin blockchain sync, the Bitcredit blockchain sync and the alignment between the two. Initial time to download and setup the blockchain can range from a day on a modern computer, or on a slow system, up to a week.
- So far the implications of using half the monetary resources of the system to secure the other half is not known. This may cause the incentive to mine to drop, and it may also cause uncertainty with regards to the valuation of one single bitcredit.
- With a direct dependency on the Bitcoin blockchain the system needs to be kept somewhat aligned with Bitcoin development. Some of the coming requirements that needs to be addressed are increasing transaction volumes, "headers first” initial download and the increasing block size.
- Storing two blockchains and keeping them synchronised requires more disk resources. For the moment an initial setup requires somewhere around 40 GB as compared to Bitcoin, which requires around 30-35 GB as of March 2015. Decreasing this difference is a high priority.
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ClaimingHow does it work?The easiest way to go about and do it is to download the Bitcredit application and start it. Once it has been started and is syncing the Bitcoin blockchain, you can take any wallet from Bitcoin and add it into the Bitcredit working directory. The wallet will be scanned for transactions as the Bitcoin blockchain download progresses. A rescan can also be invoked manually once the full blockchain has been downloaded.
The Bitcredit blockchain tracks the state of the Bitcoin blockchain approximately three months back. This means that the safest way to make a claim of bitcoins into the Bitcredit blockchain is by first making a copy of a wallet. Store the copy in a safe place. Once the copy is done, all bitcoins in the original wallet should be transferred to a new address that you have control over. After this you can import the copy of the wallet created in step one into Bitcredit and claim the coins.
Since the tracking of the Bitcoin blockchain is three months back in time you will be able to claim the coins using the copied wallet but still have a guarantee that the original bitcoins can not be touched once they have been transferred to the new (previously unused) address.
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Q&ADoes the name Bitcredit have anything to with credits as in creditor?- No. The name relates to the concept of “credits”, first made popular in Isaac Asimov’s Foundation series, and after that a common theme in movies and literature. There are no other intended associations.
Is this a sidechain?- Yes and no. It is NOT a sidechain implemented through a two-way-peg that removes coins from the Bitcoin network with the possibility to return them later. It is however, a working implementation of a one-way claiming process that taints the bitcoins that already have been claimed. This is a process that in practical terms makes Bitcredit a side chain. Sidechains that actually can move coins back and forth between chains can not be implemented in Bitcoin without major updates to the Bitcoin protocol. It can also be discussed if this actually is what one wants to achieve in a sidechain implentation, instead of giving Bitcoin users claiming possibilities in a new currency that has different properties, thereby enabling a safer transition to a new system. The Bitcredit implementation can be considered this type of "soft" sidechain implementation, since it does not destroy bitcoins. It is, to be more precise, a variant of what is described under section 3.3. Assymetric two-way-peg in the blockstream white paper on side chains.
http://www.blockstream.com/sidechains.pdf.
What do you mean by proof-of-deposit?- Proof-of-deposit communicates what is actually happening, coins are added as a deposit to a block to prove that a miner is dedicating resources to the mining process. Adding resources as a deposit means actually locking them up for an agreed period.
Could you explain a little more about the proof-of-deposit system?- The core of the block creation system is a normal proof-of-work system with an extra requirement added on top, proof-of-deposit. What this means in practical terms is that you not only have to contribute mining power but also a deposit for each block that you intend to mine. If you do not contribute a deposit that is large enough, two things will happen; the reward given for each block will decrease and the mining difficulty will increase. This means that each miner has a strong incentive to add deposits up to the required level. Each deposit will be held for approximately three months and once the time has passed the coins are released to be reused as deposit or otherwise. Under ideal circumstances at least half of all coins available will always be locked in deposit at any given point in time. Deposits are not held by any external party but are added to the blockchain itself. The proof-of-deposit system uses the total known monetary base as a parameter for calculating the deposit required for each block. The demand for deposits will grow in the same pace as new bitcredits are created.
What might the benefit of this be?- The traditional mining system of Bitcoin acts as a cap on the total validation as long as there is significant inflation in the system. To be more specific, if there are an inflation of ten percent per year, ten percent of bitcoins total value will have to be expended on mining. This induces a practical cap of the valuation of Bitcoin in direct relation to its inflation. Once the inflation drops low enough the system may instead become unstable due to low incentive for the miners.
As a contrast, with a system where large stakeholders are the key players the incentive for them will be twofold; first and foremost large stake holders will want to use their coins to produce a return and second they have an incentive to keep the system stable simply because they are large stakeholders.
What about the “nothing at stake" problem?- The Bitcredit mining system is a combination of proof-of-work and proof-of-deposit. There will be a cost involved in mining, the efforts put into mining will just be much less than for Bitcoin. The nothing at stake problem affects Bitcoin to the same extent as any other coin. If each coin has a low valuation nothing, or little, could be said to be at stake. If each coin has a higher valuation, a higher value is put at stake. Once part of the initial distribution of Bitcredit has been achieved, the nothing at stake problem probably do not apply anymore. Since the first six months are solely dependent on proof-of-work, the problem is mitigated for the initial distribution period.
What happens if no one wants to contribute enough deposits or mining power?- If not enough deposits are contributed two things will happen, the difficulty will rise for the miners not contributing enough and the reward for mining a block will drop. Entities providing enough resources will not be affected. In practice this means that if not enough resources are contributed the monetary base will not grow as fast as otherwise, and the block creation process may become slower. This will probably not occur on normal circumstances and the system will still work as intended.
Won’t the proof-of-deposit process concentrate voting power simply to large resource holders instead of large miners?- Yes, maybe. In an ideal world, the power to control the Bitcredit system will be spread across approximately 15 000 entities. When a system where coin holders can contribute with parts to the deposit (the protocol allows it today, in a safe manner), this figure could be increased to approximately 150 000 entities. Large stakeholders also have a strong incentive to keep the system stable.
Will proof-of-deposit prevent the miners from moving to specialised hardware?- Probably not. The incentive to create specialised hardware will be lower since deposits will be required, but there will still be a competitive advantage in having hardware that hashes faster.
Won’t tracking of two chains impede performance?- Maybe. At the moment there seems to be no performance issues though and the Bitcoin core developers have shown that a Bitcoin-like system is able to scale quite well.
Isn’t the connection to the Bitcoin network an extra complexity, causing extra risk?- Yes it is. However, the Bitcredit network isn’t depending on on-going mining of new Bitcoin blocks. It only requires an initial chain that is internalised once downloaded. If the creation of new Bitcoin blocks would stop, Bitcredit will continue to work independently.
What are the implications of using half of the monetary base for deposit?- Simply put, we do not know that yet. A best guess is that it will partly affect the price of one single bitcredit, but it will be quite difficult to say to what extent or how.
Does the claiming process mean that the fungibility of Bitcoin will be affected?- Yes. The claiming process will “taint” all coins that have been claimed. The claiming process is the electronic version of writing “this coin has been claimed” on a physical bank note. This tainting of coins will only be done in the Bitcredit system and do not touch the Bitcoin blockchain in any way.
What is fungibility?- Fungibility is one of the properties that make something suitable for use as a currency. More specifically, it is the interchangeability of one individual unit of a currency for another without affecting their respective value.
What do you mean by monetary base or monetary supply?- The monetary base in financial terms is roughly equivalent to all units of a currency that has been issued by a government. In the context of Bitcredit it is simply the amount of coins that has been created through mining and claiming.
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Disclaimer Bitcredit is an experimental system. Any problems may occur, including the loss of all bitcredits. Even if the Bitcoin blockchain is used solely for reading state and all other interaction with the Bitcoin system has been disabled in the client, issues may occur here as well. These issues include possible loss of some or all bitcoins used. Care must be taken when testing and it is highly recommended that ONLY small amounts are used for all testing purposes. It is also highly recommended that any bitcoins used are moved to a new address as soon as possible after testing.
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Support and developmentContributors are quite welcome. There’s currently demand for the following roles.- Developers. Catching up with the current state of the Bitcoin client is urgent. For the moment, the version of Bitcoin used internally is 0.9.1.
- Peer reviewers.
- Seeder nodes and fixed nodes to establish a more robust network.
- Graphic artists.
