Zcash addresses are either private (z-addresses) or transparent (t-addresses). Z-addresses start with a “z,” and t-addresses start with a "t." A Z-to-Z transaction appears on the public blockchain, so it is known to have occured and that the fees were paid. But the addresses, transaction amount and the memo field are all encrypted and not publicly visible. Using encryption on a blockchain is only possible through the use of zero-knowledge proofs. The owner of an address may choose to disclose z-address and transaction details with trusted third parties — think auditory and compliance needs — through the use of view keys and payment disclosure. Transactions between two transparent addresses (t-addresses) work just like Bitcoin: The sender, receiver and transaction value are publicly visible. The two Zcash address types are interoperable. Funds can be transferred between z-addresses and t-addresses.
The acronym zk-SNARK stands for “Zero-Knowledge Succinct Non-Interactive Argument of Knowledge,” and refers to a proof construction where one can prove possession of certain information, eg., a secret key, without revealing that information, and without any interaction between the prover and verifier. “Zero-knowledge” proofs allow one party (the prover) to prove to another (the verifier) that a statement is true, without revealing any information beyond the validity of the statement itself. For example, given the hash of a random number, the prover could convince the verifier that there indeed exists a number with this hash value, without revealing what it is. In a zero-knowledge “Proof of Knowledge” the prover can convince the verifier not only that the number exists, but that they in fact know such a number – again, without revealing any information about the number.
Zcash is a proof of work cryptocurrency. Zcash has a cap for the total supply of 21 million units. 20% of the coins created during 2016-2020 are allocated to founders reward shared between investors, developers, and the Zcash Foundation.
Zcash is privately owned and developed by Zerocoin Electric Coin Company (ZECC). It is US based and has to adhere to local laws, it is also funded by 20% tax that comes from mining new Zcash. Optional privacy has also significant impact on the overall privacy used in the network. Only approx. 10% of all transactions are shielded.