Tangle VS Blockchain

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BITCOIN VS IOTA

Quote from: Come-from-Beyond

Tangle vs Blockchain
Iota’s blockchain solves the following problems of its blockchain cousin:

Centralization of control
As history shows, small miners form big groups to reduce variation of the reward. This leads to concentration of power (computational and political) in hands of few pool operators and gives them ability to apply wide spectrum of policies (filtering, postponing) on certain transactions. Although there are no known cases where pool operators abused their power, there have been several instances where the opportunity were present. This possibility in a monetary system powering a multibillion (in USD) industry is completely unacceptable.

“Obsolete” cryptography
Although large scale quantum computers do not exist yet, future oriented companies have already begun initiating the steps towards quantum-resistant cryptography. From a security point of view it makes perfect sense to assume that hardware capable of cracking classical cryptoalgorithms may appear in the very near future, so preparation is the only defense.

Inability to conduct micropayments
Transaction fees are used to cover miner expenses and mitigate spam-attacks. They also set a threshold on the minimum amount of a payment below which money transfers become inexpedient.

Partition intolerance
Blockchain-based currencies are unable to survive long-sustained partitioning of the network because this may lead to reversal of a large number of transactions. It is also impossible to initiate an intentional partitioning in cases when it is required.

Discrimination of participants
Existing cryptocurrencies are heterogeneous systems with clear separation of roles (transaction issuers, transaction approvers). Such systems create unavoidable discrimination of some of their elements which in turn creates conflicts and makes all elements spend resources on conflict resolution.

Scalability limits
Some cryptocurrencies have hard limits on the maximum transaction rate and this limits cannot be removed in a decentralized manner. A magic number of a limit set before the launch cannot satisfy requirements of a system unless it is set by a person with extraordinary prediction skill. A too low value may hinder growth of the userbase, a too high value may open system to different kinds of attacks.

High requirements for hardware
Bitcoin-derived cryptocurrencies use its original script-based approach which allows implementation of a wide range of use-cases. Other currencies use an approach similar to one used by banks but add extra features. They both substantially raise requirements for hardware because of complex transaction processing logic.

Unlimited data growth
Storing of all state transitions leads to fast growth of data while does not increase stored balance information significantly. This inefficiency cannot be removed even with data pruning technique and high popularity of the currency may lead to its collapse.

http://cointelegraph.com/news/115508/iota-a-blockchain-less-gasp-token-for-the-internet-of-things