Throughput measures and the role of Tachyon
The reason for building all this is arithmetic.
Mastercard and Visa process more than 50,000 transactions per second, and the team calls that number “its bottom, not its goal.” Zcash’s current cryptography would require a node to ingest and verify more than 500 megabytes of data every second to keep up, because every private transaction has a proof, and the proofs are big.
That’s roughly a full DVD of data arriving every ten seconds, continuously, and no current Zcash software runs anywhere near that. But that missing piece is why every bottleneck exists.
Bowe’s Project Tachyon tackles this by working on recursive proofs, where one proof testifies to the validity of thousands of others, dramatically reducing the amount of data that needs to be verified by consensus.
Under Tachyon, one node verifies a single proof instead of thousands, which the team says reduces the requirement for consensus data from 100 megabytes per second to 500 megabytes, a level they claim is technically achievable with careful engineering.
Wallet bottlenecks and Valar’s PIR solution
Wallets have another problem. Because Zcash hides who a transaction is for, a wallet cannot ask a server which transactions belong to it without giving itself away. It pulls everything down and tests each one, which is why wallet software tops out at about one transaction per second.
