Monero is a privacy-preserving cryptocurrency based on the CryptoNote protocol. Its key components are anonymity, security, and fungibility. Recipients and senders of Monero use unique, one-time only, public keys for every transaction. These are called Stealth Addresses and mitigate the risks of wallet data mining, a non-trivial concern of Bitcoin users. Another feature, Ring Signatures, is also used in every transaction and is made by fusing a transaction’s actual signer with a group of random signers pulled from past transactions in the blockchain. This masks the true identities of the sender and receiver.
Zcash is a privacy preserving digital currency and the first to use Zero Knowledge Proofs to obfuscate the identities of parties to a transaction. Zcash uses zk-SNARKs, a variant of Zero Knowledge Proofs, to prove that the conditions for a valid transaction have been met without revealing any crucial information about the addresses or values involved. Even though Zcash transactions require additional computation to be processed, the architecture of its blockchain guarantees a level of privacy that cannot be matched by other privacy-preserving technologies, including Monero’s Ring Signatures. The protocol known today as Zcash was initially developed under the name Zerocoin, a collaboration between researchers at Johns Hopkins University, a group of cryptographers at the Massachusetts Institute of Technology, students at the Israel Institute of Technology, and Tel Aviv University. The genesis block of Zcash was mined in October 2016.
Dash is one of the oldest and largest cryptocurrencies. It was originally created to address the lack of anonymity in the Bitcoin network and its PrivateSend application is one of its most popular features. The protocol also features nearly instantaneous transactions, called InstantSend. These two features, along with traditional transactions, make Dash unique in the digital asset ecosystem. Both InstantSend and PrivateSend are enabled by masternodes, which are like centralized servers in the Dash network, a structure pioneered by the protocol and now embraced by other cryptocurrencies. However, Dash’s privacy features are not as robust as other privacy preserving currencies, like Monero or Zcash. PrivateSend is a form of transaction mixing, one of the oldest privacy preserving techniques, and falls short when compared to more modern techniques. Those new to cryptocurrencies probably are unaware of Dash controversial origins. Originally launched in early 2014 as a fork of Litecoin under the name “XCoin”, a large number of tokens, approximately 24% of the current supply base ($1.4B at today’s price), was mined in the first 24 hours in what is now called “the Instamine.” “XCoin” went on to rebrand as “Darkcoin” and then finally as “Dash”, short for “digital cash.” One of the things we think that Dash got right was their focus on community building since digital assets benefit from network effects.