Throughput goals and role of Tachyon
The reason for all this is arithmetic.
Mastercard and Visa process more than 50,000 transactions per second, and the team calls that number “its floor, not its target.” Zcash’s current cryptography would require a node to retrieve and verify over 500 megabytes of data every second to keep up, because every private transaction has a proof, and proofs are large.
That’s roughly a full DVD of data arriving every ten seconds, continuously, and no current Zcash software performs at that level. But the missing piece is the reason each bottleneck exists.
Bowe’s Tachyon Project is tackling this problem by working on recursive proofs, in which one proof attests to the validity of thousands of others, thereby significantly reducing the amount of data that must be verified by consensus.
Under Tachyon, a node verifies a single proof instead of thousands, which the team says reduces the need for consensus data from 100 megabytes per second to 500 megabytes, a level they say is technically achievable through careful engineering.
Valar’s Portfolio Bottlenecks and PIR Solution
Wallets have a different problem. Because Zcash hides who a transaction is for, a wallet cannot ask a server which transactions belong to it without revealing itself. It mines everything and tests each one, which is why the wallet software achieves around one transaction per second.
