{"id":56089,"date":"2025-10-31T23:31:33","date_gmt":"2025-10-31T23:31:33","guid":{"rendered":"https:\/\/dogewisperer.com\/?p=56089"},"modified":"2025-10-31T23:31:33","modified_gmt":"2025-10-31T23:31:33","slug":"is-zcash-quantum-resistant-yet-experts-weigh-in","status":"publish","type":"post","link":"https:\/\/dogewisperer.com\/?p=56089","title":{"rendered":"Is Zcash Quantum-Resistant Yet? Experts Weigh In"},"content":{"rendered":"
\n

A debate on X this week exposed a core question for on-chain privacy: when quantum computers are able to break elliptic-curve cryptography (ECC), will they be able to retroactively deanonymize every transaction ever made of privacy coins like Zcash?<\/p>\n

Nic Carter, co-founder of Coin Metrics and partner at Castle Island Ventures, argued <\/a>that the answer is effectively yes for most privacy coins. \u201cFor privacy coins, even if they migrate to post-quantum cryptographic schemes, all historical transactions prior to that migration can be decrypted,\u201d he said on October 30, 2025. \u201cSo all historical txns will be stripped of privacy in >~5y. Everything is built on ECC.\u201d<\/p>\n

Carter\u2019s point is based on \u201charvest now, decrypt later.\u201d Attackers don\u2019t need to break you today. They just copy the data now and crack it once quantum is strong enough. On blockchains, that problem is worse<\/a> because the data is already public and permanent. \u201cBlockchains are uniquely bad for quantum because normally the quantum thing is \u2018harvest now decrypt later\u2019 so adversaries have to be preemptively harvesting traffic but blockchains just.. publish.. everything.. forever.\u201d<\/p>\n

He warned specifically that even if a privacy coin upgrades to quantum-resistant signatures in the future, old activity is still exposed once ECC falls. \u201cWhile privacy coins can adopt post quantum sigs, understand that all previously hidden addresses, relationships between addresses, etc, will be revealed once ECC is broken,\u201d Carter said. \u201cAnd obviously everything is on chain so you don\u2019t even need to harvest traffic today.\u201d<\/p>\n

Is Zcash Already Quantum-Resistant?<\/h2>\n

That claim triggered pushback from Zcash supporters, who argue Zcash is structurally different<\/a> from something like Monero.<\/p>\n

Mert Mumtaz (Helius) agreed that Carter\u2019s warning applies to \u201cmany privacy coins like Monero<\/a>,\u201d but said it\u2019s \u201cnot necessarily true for zcash\u2019s privacy, given advanced opsec.\u201d He acknowledged that \u201cadvanced opsec is not the norm,\u201d but said that if it is followed, Zcash users \u201cget you certain guarantees w.r.t information leakage.\u201d He also said \u201csome things are in the works to make this even stronger,\u201d pointing to research by Zcash engineer Sean Bowe.<\/p>\n

Bowe\u2019s position is that Zcash\u2019s fully shielded pool simply does not put critical sender\/receiver information on the ledger in the first place. \u201cThere is no quantum computer or powerful AI that will be able to look back at the Zcash blockchain 1000 years from now and figure out who made every fully shielded transaction,\u201d Bowe said in July this year. \u201cThat information, among other things, never even touches the ledger. It\u2019s already gone.\u201d His condition is clear: \u201cTo be certain about your privacy you must start by using shielded Zcash. You almost cannot even begin otherwise.\u201d<\/p>\n

Carter partially credits that. \u201cZec is definitely ahead of anyone when it comes to quantum preparedness, not denying that,\u201d he said. But he called the \u201calready quantum-proof\u201d framing unrealistic in practice.<\/p>\n

He argued that Zcash\u2019s long-term privacy story depends on very strong assumptions that often break in the real world: \u201cassumes pubkey never being known. assumes: no metadata collection, no exchange key leaks, perfect metadata privacy.\u201d<\/p>\n

He added that Zcash\u2019s shielded pools \u2014 Sprout, Sapling, Orchard \u2014 still \u201crely on ECC for key exchange, viewkeys, proof verification, which are all broken\u201d under a powerful quantum adversary. His conclusion: \u201cunrealistic to say zec privacy is perfectly q resistant. linkages between addrs are forever encoded on the blockchain, you and Sean know that. store now decrypt later still applies.\u201d<\/p>\n

In other words: Zcash builders say that if you stay fully shielded, the chain itself won\u2019t hand quantum attackers a clean map of who paid whom. Carter says that in the real world, users leak, exchanges leak, metadata leaks \u2014 and once ECC breaks, those leaks plus the permanent ledger are enough to unwind the privacy anyway.<\/p>\n

One final note: when asked directly, Carter denied holding ZEC. \u201cNope.\u201d<\/p>\n

At press time, ZEC traded at $366.<\/p>\n

\"Zcash<\/div>\n","protected":false},"excerpt":{"rendered":"

A debate on X this week exposed a core question for on-chain privacy: when quantum computers are able to break elliptic-curve cryptography (ECC), will they be able to retroactively deanonymize every transaction ever made of privacy coins like Zcash? Nic Carter, co-founder of Coin Metrics and partner at Castle Island Ventures, argued that the answer […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":0,"footnotes":""},"categories":[2],"tags":[3,4,5],"class_list":["post-56089","post","type-post","status-publish","format-standard","hentry","category-news","tag-crypto","tag-doge","tag-news"],"_links":{"self":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/posts\/56089","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=56089"}],"version-history":[{"count":0,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/posts\/56089\/revisions"}],"wp:attachment":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=56089"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=56089"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=56089"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}