FROST
TL;DR
- FROST (Flexible Round-Optimised Schnorr Threshold Signatures) yɛ threshold signature ne distributed key generation protocol: wɔn a wɔde wɔn nsa ahyɛ aseɛ dodoɔ bi mu biara kura kyɛfa wɔ kokoam safoa a wɔbom yɛ mu, na ɛsɛ sɛ wɔn mu threshold nɔma bi yɛ adwuma bom na ama wɔayɛ nsaano nkyerɛwee baako.
- Esiane sɛ nea efi mu ba ne Schnorr nsaano nkyerɛwee biako nti, asɛm a wɔayɛ no saa kwan yi so no te sɛ asɛm a wɔyɛ no kwa wɔ ntwamutam no so.
- Ɛhwehwɛ sɛ wɔde nkitahodi kakraa bi na ɛyɛ, ebetumi atu mmirika bere koro mu, na ebetumi ahu obi a ɔde ne ho hyɛ mu a ɔbɔ bra bɔne na ayi no afi mu.
- Wɔ Zcash fam no, eyi kyerɛ sɛ FROST ma afã horow pii, a wɔatew wɔn ho wɔ asasesin mu no tumi di sika a wɔsɛe no tumi a ɛwɔ ZEC a wɔabɔ ho ban no so — mfaso wɔ so ma sikakorabea, escrow, nnwuma a ɛnyɛ sikakorabea, ne Zcash Shielded Assets (ZSA).
- It was created by Chelsea Komlo (University of Waterloo, Zcash Foundation) and Ian Goldberg (University of Waterloo).
Nkyerɛkyerɛmu Titiriw
Dɛn ne Schnorr nsaano nkyerɛwee?
Schnorr dijitaal nsaano nkyerɛwee yɛ nhyehyɛe ahorow a wɔahyehyɛ: (KeyGen, Sign, Verify).
Schnorr nsaano nkyerɛwee wɔ mfaso pii. Mfaso titiriw biako ne sɛ, sɛ wɔde nsafe pii di dwuma de hyɛ nkrasɛm koro ase a, wobetumi de nsaano nkyerɛwee a efi mu ba no abom ayɛ no nsaano nkyerɛwee biako. Eyi betumi atew multisig sikatua ne nnwuma afoforo a ɛfa multisig ho no kɛse so kɛse.
Dɛn ne FROST?
Schnorr Threshold Nsɛnkyerɛnne a Ɛyɛ Nsakrae Kurukuruwa-Optimised - .
Created by Chelsea Komlo (University of Waterloo, Zcash Foundation) & Ian Goldberg (University of Waterloo).
FROST yɛ threshold signature ne distributed key generation protocol a ɛhia nkitahodi rounds kakraa bi na wobetumi ayɛ no parallel. FROST protocol yɛ Schnorr nsaano nkyerɛwee nhyehyɛe no threshold version.
Nea ɛnte sɛ nsaano nkyerɛwee a ɛwɔ ɔfã biako tebea mu no, ahyɛnsode nsaano nkyerɛwee hwehwɛ sɛ wɔn a wɔde wɔn nsa hyɛ ase no dodow bi a wɔde wɔn nsa hyɛ ase no yɛ biako, na wɔn mu biara kura kokoam safe biako mu kyɛfa.
Dɛn ne Threshold Signatures? Chelsea Komlo - Ɔde ne nsa kyerɛɛ ne so
Ne saa nti, sɛ wɔyɛ nsaano nkyerɛwee wɔ threshold nhyehyɛe mu a, ɛde sika pii ba esiane ntwamutam a ɛkɔ so wɔ wɔn a wɔde wɔn nsa hyɛ ase no mu nti, na ɛma ɛyɛ den bere a wɔde kokoam kyɛfa sie wɔ mfiri a ntwamutam anohyeto wom so anaasɛ bere a nkitahodi kɔ so wɔ ntwamutam a wontumi mfa ho nto so so.
Network overhead bere a signing adwumayɛ no so tew denam ɔkwan foforo a wɔde di dwuma a ɛbɔ ho ban fi atoro ntua ho na ɛfa nhyehyɛe afoforo nso ho.
FROST ma threshold signature protocols tu mpɔn denam ma a ɛma kwan ma wɔyɛ signature dwumadie dodoɔ a anohyetoɔ nni mu dwoodwoo wɔ parallel (concurrency) mu.
Wobetumi de adi dwuma sɛ 2-round protocol, baabi a signers de nkrasɛm 2 mena na wogye nyinaa, anaasɛ sɛ optimized single-round signing protocol a ɛwɔ preprocessing stage.
FROST nya ne nkɔsoɔ a ɛba wɔ adwumayɛ mu no fã bi denam ma a ɛma protocol no gyae nyinsɛn wɔ obi a ɔde ne ho hyɛ mu a ɔnyɛ abrabɔ bɔne anim, a afei wɔhunu no na wɔyi no firi daakye dwumadie mu.
Wɔde ahobammɔ ho adanse a ɛkyerɛ sɛ FROST wɔ ahobammɔ wɔ ntua a wɔapaw ho, a yɛfa no sɛ discrete logarithm haw no yɛ den, na ɔtamfo no di wɔn a wɔde wɔn ho hyɛ mu kakraa bi so sen threshold no ama ha.
Ɔkwan bɛn so na FROST yɛ adwuma?
FROST protocol no kura nneɛma abien a ɛho hia:
Nea edi kan no, n a wɔde wɔn ho hyɛɛ mu no yɛ distributed key generation (DKG) protocol de yɛ common verification key. Wɔ awiei no, obiara a ɔde ne ho hyɛ mu no nya kokoam kokoam safe kyɛfa ne ɔmanfo nokwaredi safe kyɛfa.
Ɛno akyi no, t-out-of-n participants biara betumi ayɛ threshold signing protocol de ayɛ adwuma abom ayɛ Schnorr signature a ɛfata.
Aniwa so / Nsɛso
Fa no sɛ FROST te sɛ safe-deposit box a ɛbue bere a keyholders pii a wɔama wɔn tumi dan wɔn safe no bom nkutoo — nanso ɛnyɛ keyholder biara na wɔhwehwɛ; nɔma a wɔahyɛ no ara kwa (sɛ nhwɛso no, 5 biara mu 3). Sɛ wobue adaka no wie a, obi a ɔhwɛ abɔnten ntumi nhu safe a wɔde kuraa mu a wɔdaa no adi, anaasɛ mpo sɛ ɛboro biako na wɔde wɔn ho hyɛɛ mu. Saa ara nso na kuw bi betumi abom ama Zcash asɛm bi ho kwan bere a ntwamutam no hu nsaano nkyerɛwee biako pɛ a ɛte sɛ nea ɛyɛ mpapahwekwa.
Deep Dive a Wɔde Nsu Gu Mu
Awoɔ ntoatoasoɔ safoa a wɔakyekyɛ (DKG)
Botae a ɛwɔ saa ɔfa yi mu ne sɛ ɛbɛma wɔanya kokoam safoa kyɛfa a ɛtra hɔ kyɛ ne safe a wɔde di adanse a wɔbom yɛ. Saa fa yi, n a wɔde wɔn ho hyɛ mu na wɔhwɛ so.
FROST kyekye n’ankasa awo ntoatoaso titiriw fã wɔ Pedersen DKG (GJKR03), a ɛde Shamir kokoam kyɛfa ne Feldman kokoam kyɛfa nhyehyɛe a wotumi di ho adanse nyinaa di dwuma sɛ subroutines. Bio nso, ɛsɛ sɛ obiara a ɔde ne ho hyɛ mu no da nimdeɛ a ɔwɔ wɔ n’ankasa ahintasɛm ho adi denam adanse a nimdeɛ biara nnim a ɔde bɛmena wɔn a wɔde wɔn ho hyɛɛ mu afoforo no so, a ɛno ankasa yɛ Schnorr nsaano nkyerɛwee. Saa anammɔn foforo yi bɔ ho ban fi rogue-key ntua ho bere a t ≥ n/2.
Wɔ DKG protocol no awiei no, wɔyɛ joint verification key vk. Obiara a ɔde ne ho hyɛ mu Pᵢ kura botaeɛ (i, skᵢ ) a ɛyɛ wɔn kokoam kyɛfa a ɛtra hɔ kyɛ ne verification key share vkᵢ = skᵢ *G. Ɔdefoɔ Pᵢ no verification key share vkᵢ no, afoforɔ a wɔde wɔn ho hyɛ mu no de di dwuma de hwɛ sɛ Pᵢ nsaano nkyerɛwee kyɛfa no teɛ wɔ signing phase no mu, berɛ a verification key vk no, abɔnten sofoɔ de di dwuma de hwɛ sɛ nsaano nkyerɛwee a kuw no de ama no yɛ nokware.
Aboboano Nsɛnkyerɛnne
Saa fa yi gyina akwan a wonim a ɛde additive secret sharing ne share conversion di dwuma de non-interactively generate the nonce ma signature biara. Ɛsan nso de akwan horow a wɔfa so kyekyere nneɛma di dwuma de kwati ntua a wonim sɛ ɛyɛ atoro a ɛntoto nneɛma a ɛkɔ so bere koro mu ano.
Wɔ preprocessing stage no mu no, obiara a ɔde ne ho hyɛ mu no siesie Elliptic Curve (EC) nsɛntitiriw abien abien dodow bi a wɔahyɛ ato hɔ ma wɔde adi dwuma akyiri yi. Saa fã yi tu mmirika pɛnkoro wɔ threshold signing phases pii so.
Signing Round 1: Obiara a ɔde ne ho hyɛ mu no Pᵢ fi ase denam kokoam nonce baanu biako (dᵢ, eᵢ) ne EC nsɛntitiriw abien a ɛne no hyia (Dᵢ, Eᵢ) a ɔde bɛma so, afei ɔde saa nsɛntitiriw abien yi kɔma wɔn a wɔde wɔn ho hyɛɛ mu afoforo nyinaa. Obiara a ɔde ne ho hyɛ mu no de EC nsɛntitiriw abien yi sie ma ɔde bedi dwuma akyiri yi. Signing rounds 2 ne 3 yɛ adwumayɛ ankasa a t-out-of-n a wɔde wɔn ho hyɛ mu no yɛ biako de yɛ Schnorr nsaano nkyerɛwee a ɛfata.
Signing Round 2: Wɔn a wɔbɛkɔ bi no bom yɛ adwuma de yɛ Schnorr nsaano nkyerɛwee a ɛfata. Ɔkwan titiriw a ɛwɔ saa round yi akyi ne t-out-of-t additive secret sharing.
Saa anammɔn yi siw atoro ntua ano efisɛ ntuafo ntumi nka nsaano nkyerɛwee kyɛfa nkabom wɔ nsaano nkyerɛwee dwumadi ahorow mu anaasɛ wɔnsakra wɔn a wɔde wɔn nsa hyɛɛ ase no nhyehyɛe anaa nsɛntitiriw a wɔatintim mma obiara a ɔde ne nsa hyɛɛ ase no.
Bere a wabu asɛnnennen c no, obiara a ɔde ne ho hyɛɛ mu no betumi de nonces a wɔde di dwuma pɛnkoro ne kokoam kyɛfa a wɔde di dwuma bere tenten, a ɛyɛ t-out-of-n (degree t-1) Shamir kokoam kyɛfa a ɛwɔ kuw no safoa a ɛtra hɔ kyɛ no so abu mmuae zᵢ no ho akontaa. Wɔ nsaano nkyerɛwee round 2 awiei no, obiara a ɔde ne ho hyɛ mu no bɔ zᵢ kyerɛ wɔn a wɔde wɔn ho hyɛɛ mu afoforo.
Kenkan krataa no nyinaa
FROST a wɔde di dwuma wɔ abɔde a nkwa wom a ɛtrɛw no mu
FROST wɔ Coinbase mu
Sɛnea ɛbɛyɛ a Coinbase threshold-signing systems no bɛyɛ adwuma yiye no, wɔyɛɛ FROST bi. Saa Coinbase dwumadie yi yɛ nsakraeɛ kakra firi mfitiaseɛ FROST draft no mu.
Wɔpaw sɛ wɔremfa nsaano nkyerɛwee a wɔboaboa ano dwumadi no nni dwuma. Mmom no, obiara a ɔde ne ho hyɛ mu no yɛ obi a ɔboaboa nsaano nkyerɛwee ano. Saa nhyehyeɛ yi yɛ ahobanbɔ kɛseɛ: wɔn a wɔde wɔn ho hyɛ protocol no mu nyinaa di afoforo akontabuo ho adanseɛ, na wɔnam saayɛ so nya ahobanbɔ a ɛkorɔn na asiane so tew. Woyii preprocessing stage a na wɔyɛ pɛnkoro no nso fii hɔ sɛnea ɛbɛyɛ a wɔde bedi dwuma ntɛmntɛm, na wɔde signing round a ɛto so abiɛsa dii dwuma mmom.
TOTO Blockstream na ɔkyerɛwee
Wɔahyɛ nyansa sɛ wɔmfa nkɔsoɔ a ɛfa dwumadie pɔtee bi ho wɔ FROST so mfa nni dwuma wɔ Blockstream Liquid Sidechain ma Bitcoin.
"ROAST yɛ ade a ɛnyɛ den a wɔde kyekyere threshold signature schemes te sɛ FROST. Ɛma awerɛhyem sɛ quorum a ɛyɛ nokwaredifo a wɔde wɔn nsa hyɛ ase, e.g., Liquid adwumayɛfo no, betumi anya nsaano nkyerɛwee a ɛfata bere nyinaa wɔ mpo wɔ hɔ a disruptive signers wɔ hɔ bere a network connections wɔ arbitrarily high latency."
FROST wɔ IETF mu
Intanɛt Mfiridwuma Adwumakuo a wɔde sii hɔ wɔ afe 1986 mu no ne ahyehyɛdeɛ a ɛdi kan a ɛma wɔyɛ gyinapɛn ma Intanɛt. IETF no yɛ gyinapɛn ahorow a wofi wɔn pɛ mu yɛ a wɔn a wɔde Intanɛt di dwuma, wɔn a wɔyɛ nkitahodi nhyehyɛe, ne wɔn a wɔtɔn nnwinnade taa gye tom, na ɛboa ma wɔyɛ Intanɛt no kwan.
Wɔde FROST version 11 (a ɛyɛ abien-round variant) wɔde akɔma IRTF. Eyi yɛ anammɔn a ɛho hia a ɛbɛma wɔayɛ FROST nhwehwɛmu a edi mũ sɛ threshold signature scheme gyinapɛn foforo a wɔde bedi dwuma wɔ intanɛt so, wɔ hardware mfiri mu, ne nnwuma afoforo mu wɔ mfe a ɛreba no mu.
Nkyerɛkyerɛmu a mfaso wɔ so
Yiw koraa. FROST a wɔde bɛba Zcash no bɛma akuo ahodoɔ pii, a wɔatew wɔn ho wɔ asasesin mu, atumi adi sika a wɔsɛe no tumi a ɛwɔ ZEC a wɔabɔ ho ban no so. Nkitahodi a wɔde saa nsaano nkyerɛwee nhyehyɛe yi bɛbɔ amanneɛ no, wɔrenhu nsonsonoe a ɛda nnwuma afoforo a ɛwɔ ntam no ntam, na ɛbɛkɔ so asɔre atia sikatua akyi a wodi no denneennen na ɛto blockchain data dodow a ɛwɔ hɔ ma nhwehwɛmu no ano hye.
Wɔ nnwuma mu no, eyi ma wotumi sisi application foforo pii wɔ network no so, efi escrow providers so kosi nnwuma afoforo a ɛnyɛ custodial so.
FROST nso bɛyɛ ade titiriw wɔ Zcash Shielded Assets (ZSA) a wɔde ma ne ne sohwɛ a ahobanbɔ wom mu, a ɛbɛma wɔatumi adi sika a wɔsɛe no tumidi ho dwuma a ahobammɔ wom wɔ nkɔso orgs & ZEC ahwɛfo te sɛ exchanges mu, bere a ɛsan nso de saa tumi yi ma Zcash dwumadiefoɔ.
Mfomso a Ɛtaa Tu
FROST a ɛyɛ basaa ne atetesɛm on-chain multisig. Amanneɛ kwan so multisig betumi ada nnipa pii a wɔde wɔn nsa ahyɛ ase anaasɛ nsaano nkyerɛwee pii adi wɔ nkɔnsɔnkɔnsɔn so. FROST ma Schnorr nsaano nkyerɛwee biako a wɔaboaboa ano, enti wontumi nhu nsonsonoe a ɛda asɛm bi ne nsaano nkyerɛwee biako ntam.
Fa no sɛ kakraa bi sen threshold no betumi de wo nsa ahyɛ ase. Threshold number (t-out-of-n) a ɛfa wɔn a wɔde wɔn ho hyɛɛ mu a wɔbom yɛ ade nkutoo na ebetumi ama wɔanya nsaano nkyerɛwee a ɛfata; kuw ketewaa biara ntumi nyɛ saa.
Sɛ yɛfa no sɛ FROST de biribiara sie off-chain. FROST bɔ nsaano nkyerɛwee a ɛwɔ nkɔnsɔnkɔnsɔn so no ho ban, nanso nkitahodi a ɛda wɔn a wɔde wɔn nsa hyɛ ase ntam no da so ara kɔ so wɔ nkɔnsɔnkɔnsɔn no akyi na ɛhwehwɛ sɛ ɔhwɛ n’ankasa kokoam nsɛm ne ahobammɔ so.
Nkratafa a Ɛfa Ho
Adesua a Ɛkɔ Akyiri
Coinbase Asɛm - Threshold Nsaano Nkyerɛwee
Shamir Ahintasɛm Kyɛ - Nkyerɛkyerɛmu & Nhwɛso
Video Tiawa a ɛfa Schnorr Digital Signatures ho
