The team behind Zakura, a Zcash full node, said it plans to bring post-quantum signature opcodes to Zcash in January to protect funds held in transparent addresses. “Our team plans for post-quantum signature opcodes to land in Zcash in January,” Roman Akhtariev wrote in an engineering post. The post named no Mainnet activation date.
The post said full post-quantum-safe transparent pools using hash-based signatures are targeted for January. In the meantime, it said, wallets can pair a hash-based signature scheme called WOTS with the usual elliptic-curve key to get post-quantum-safe rotating transparent addresses today, though no integrated wallet flow for that exists yet.
Get Unchained’s crypto news in your inbox with the free Unchained Daily newsletter.
Rotating Addresses, Private Lookups
A transparent Zcash address holds a hash of a public key, and spending from it publishes that key, Zakura said. Funds left at an address after a spend can go to a new address whose public key is still undisclosed, Zakura said. The post said that adds protection if public keys can be attacked but the hashes stay secure.
The catch is lookups. A wallet that checks many rotating addresses through an ordinary server request tells that server the addresses share one owner, even if the chain shows no link.
Zakura’s answer is private information retrieval (PIR), which lets a wallet fetch a record without the server learning which one. Confirmed transparent activity is split into block ranges, each served by a shard that publishes a compact filter the wallet checks locally. The wallet makes a private lookup only when a filter signals a possible match. Zakura said a range with 10,000 distinct payment scripts needs roughly 15 KB of filter data.
The same method can rebuild a wallet’s history from a mnemonic, including addresses that now hold nothing, the post said.
The post said the PIR component is coming to the Vizor wallet, and an experimental version can already be tested by turning on “Private queries” in settings.
Context
Ethereum Foundation researcher Justin Drake called on the industry on Oct. 7 to begin planning for “bunker mode,” an effort to shift funds into fresh addresses that have never signed a transaction. He said it is reasonable to brace for ECDSA breaking before quantum computers arrive, in the worst case “in months not years,” and urged holders not to rush or panic.
Transparent Zcash transactions stay public on-chain, Zakura said. PIR protects the lookups wallets use to manage them.
Related Listen: One Type of Post-Quantum Cryptography Is Most Popular. Why Is Crypto Trying Out Three?
The post Zcash Node Team Targets January for Post-Quantum Signatures on Transparent Addresses appeared first on Unchained.
Powered by WPeMatico
