30.Identity and Anonymity on Blockchain: Anonymity in the Blockchain скачать в хорошем качестве

30.Identity and Anonymity on Blockchain: Anonymity in the Blockchain

************************************************************* Source: EDX LinuxFoundationX LFS170x Blockchain: Understanding Its Uses and Implications ************************************************************ A) The following are only some of the mechanisms developed and implemented in various blockchains: 1- Zero-Knowledge Proofs A prover proves knowledge of a secret without revealing it. Zero-knowledge proofs use cryptographic algorithms to allow a user to prove knowledge of a secret without revealing the secret. 2- Stealth Addresses Using one-time addresses for sending/receiving transactions for an account. Stealth addresses involve using one-time addresses to perform transactions on a blockchain. A stealth address is just a one-time address that makes it impossible to link a transaction to a known account. This prevents the data mining attacks on privacy that we discussed earlier. 3- Ring Signatures Type of digital signatures that lets any member of the group sign, but no one can tell which one signed. We mentioned previously that transactions are digitally signed. With ring signatures, all that can be determined from a transaction is that a member of a group signed it, but not the particular member. 4- CoinJoin Transactions from several senders to several recipients are mixed together to hide who is paying whom. The ability to see who is performing transactions with whom is dangerous to user privacy and anonymity. Protocols like CoinJoin mix several transactions together so that it is difficult to pair senders with recipients. 5- Confidential Transactions Uses homomorphic encryption to allow transactions to be processed while encrypted. Proves transaction value is in a range of values to prove that overspending did not occur. Confidential transactions take advantage of homomorphic encryption, which makes it possible to perform mathematical operations on encrypted data. This means that the data contained in a transaction can be hidden from the public, while still allowing the network to verify that the transaction is valid. B) Specific Anonymity Implementations 1) Ethereum Ethereum currently does not have any advanced privacy options, but this is planned to change. 2) Hyperledger 2.1) Channels: Subsections of the blockchain that make transactions visible only to members. 2.2) Private Transactions: Hashes of private data are stored to publicly verify it on the blockchain. 2.3) Zero-Knowledge Technology: Provers can demonstrate knowledge of a secret without revealing the secret itself. 3) Corda Parties on the Corda Network can be represented in one of two ways: 3.1) Party: A public key and name 3.2) Anonymous Party: Only a public key.