In September 2015 Bitcoin Magazine reviewed a conversation with legendary cryptographer Adam Back on the Bitcoin Knowledge Podcast, hosted by Trace Mayer. Back is known as the inventor of Hashcash, the proof-of-work system used by Bitcoin and other cryptocurrencies as part of the mining algorithm, one of the authors of the Bitcoin Sidechains white paper “ Enabling Blockchain Innovations with Pegged Sidechains ” and one of the founders of Blockstream . In the September podcast, he mentioned Zerocash, a recent development in cryptography that could be applied to new privacy-preserving cryptocurrencies.
The Zerocash protocol has been considered one of the most promising technologies for putting privacy back into the Bitcoin equation. Now, the Zerocash project has announced that the protocol is being developed into a full-fledged digital currency, Zcash .
According to the recently launched website, Zcash is “a decentralized and open-source cryptocurrency that aims to set a new standard for privacy and anonymity through the use of groundbreaking cryptography.”
A public alpha technology preview has been released on Github .
Zcash offers total payment confidentiality, while maintaining a decentralized network using a public blockchain. Unlike Bitcoin, Zcash transactions automatically hide the sender, recipient and value of all transactions on the blockchain. Only those with the correct view key can see the contents. Users have complete control and can opt-in to provide others with their view key at their discretion.
To achieve the (previously) impossible dream, Zcash uses a zero-knowledge proof construction called a zero-knowledge Succinct Non-interactive ARguments of Knowledge (zk-SNARK), described in the Zerocash technical paper , first presented at the 2014 IEEE Security & Privacy Symposium. zk-SNARKs allow the Zcash network to maintain a secure ledger of balances without disclosing the parties or amounts involved. Instead of publicly demonstrating spend-authority and transaction values, the transaction metadata is encrypted and zk-SNARKs are used […]
