[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-572107-105":3,"detail-sidebar-cat-1-en-105":80,"doc-detail-572107-en":126},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":73,"head_meta":75,"extra_data":77,"updated_unix":79},105,"en","qatsi-stateless-secret-generation-via-hierarchical-memory-hard-key-derivation","Qatsi: Stateless Secret Generation via Hierarchical Memory-Hard Key Derivation","","Qatsi introduces a hierarchical key-derivation scheme built on Argon2id to generate reproducible cryptographic secrets without any persistent storage. Secrets are deterministically derived from a single high-entropy master credential combined with contextual layers, removing vault-based attack surfaces. The outputs provide 103–312 bits of entropy using memory-hard parameters (64–128 MiB, 16–32 iterations) and provably uniform rejection sampling over 7776-word mnemonics or 90-character passwords. The paper formalizes uniformity, quantifies GPU costs, and presents a Rust implementation with zeroization, integrity checks, and benchmarks.",{"@graph":14,"@context":72},[15,34,55],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/template/","Template",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/template/general/","General",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/template/qatsi-stateless-secret-generation-via-hierarchical-memory-hard-key-derivation/572107/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/qatsi-stateless-secret-generation-via-hierarchical-memory-hard-key-derivation/572107.png","ImageObject",442,249,{"name":42,"@type":43},"Danger Angel","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-21","2026-10-13",true,{"@type":52,"interactionType":53,"userInteractionCount":26},"InteractionCounter",{"@type":54},"ViewAction",{"@type":56,"mainEntity":57},"FAQPage",[58,64,68],{"name":59,"@type":60,"acceptedAnswer":61},"What is Qatsi, and what core goal does it target?","Question",{"text":62,"@type":63},"Qatsi is a hierarchical key-derivation scheme that generates reproducible cryptographic secrets without persistent storage. It targets high-stakes, stateless master credential generation where deterministic reproducibility outweighs rotation flexibility.","Answer",{"name":65,"@type":60,"acceptedAnswer":66},"How does Qatsi resist attacks compared with traditional deterministic schemes?",{"text":67,"@type":63},"Qatsi uses Argon2id with memory-hard derivation, forcing attackers to allocate comparable memory per guess. It also applies hierarchical context layers derived deterministically from a single master secret.",{"name":69,"@type":60,"acceptedAnswer":70},"What parameters and output formats does the paper report for entropy and usability?",{"text":71,"@type":63},"The paper reports 103–312 bits of entropy using memory-hard settings such as 64–128 MiB and 16–32 iterations. It supports word-based mnemonic outputs (7776-word set) and 90-character password outputs, with benchmarks reported on Apple M1 Pro for Standard and Paranoid modes.","https://schema.org",{"og:url":32,"og:type":74,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":76,"canonical":32},"index,follow",{"doc_id":78,"site_id":7},572107,1792589889,{"code":4,"msg":81,"data":82},"success",[83,88,93,98,103,108,113,118,123],{"id":84,"doc_module":22,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},11,"Presentations",90,"presentations",{"id":89,"doc_module":22,"doc_module_name":25,"category_name":90,"show_sort_weight":91,"slug":92},12,"Resumes",80,"resumes",{"id":94,"doc_module":22,"doc_module_name":25,"category_name":95,"show_sort_weight":96,"slug":97},14,"Invoices",70,"invoices",{"id":99,"doc_module":22,"doc_module_name":25,"category_name":100,"show_sort_weight":101,"slug":102},15,"Posters",60,"posters",{"id":104,"doc_module":22,"doc_module_name":25,"category_name":105,"show_sort_weight":106,"slug":107},16,"Social Media",50,"social-media",{"id":109,"doc_module":22,"doc_module_name":25,"category_name":110,"show_sort_weight":111,"slug":112},17,"Forms",40,"forms",{"id":114,"doc_module":22,"doc_module_name":25,"category_name":115,"show_sort_weight":116,"slug":117},18,"Letters",30,"letters",{"id":119,"doc_module":22,"doc_module_name":25,"category_name":120,"show_sort_weight":121,"slug":122},21,"Paper Templates",5,"papers-templates",{"id":124,"doc_module":22,"doc_module_name":25,"category_name":29,"show_sort_weight":4,"slug":125},158,"general-158",{"code":4,"msg":81,"data":127},{"doc_id":78,"user_id":128,"nickname":42,"user_avatar":129,"doc_module":22,"category_id":124,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":130,"file_id":131,"file_url":132,"file_type":133,"file_size":134,"view_count":26,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":84,"language":135,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":136,"faqs":137,"seo_title":138,"seo_description":12,"update_tm":139,"read_time":33},962090769052,"https://ap-avatar.wpscdn.com/davatar_9964176cb1d06d4a9deccf72a44ae3dc","Qatsi: Stateless Secret Generation via Hierarchical Memory-Hard Key Derivation  \nRené Coignard∗ Independent Researcher Dessau-Roßlau, Germany  \nAnton Rygin† Technische Universität Dresden Berlin, Germany  \narXiv :2510 . 18614v1 [ cs .CR] 21 Oct 2025  \n[https://github.com/coignard/qatsi](https://github.com/coignard/qatsi)  \nOctober 2025  \nAbstract  \nWe present Qatsi, a hierarchical key derivation scheme using Argon2id that generates reproducible cryptographic secrets without persistent storage. The system eliminates vaultbased attack surfaces by deriving all secrets deterministically from a single high-entropy master secret and contextual layers. Outputs achieve 103–312 bits of entropy through memory-hard derivation (64–128 MiB, 16–32 iterations) and provably uniform rejection sampling over 7776-word mnemonics or 90-character passwords. We formalize the hierarchical construction, prove output uniformity, and quantify GPU attack costs: 2.4 × 1016 years for 80-bit master secrets on single-GPU adversaries under Paranoid parameters (128 MiB memory) . The implementation in Rust provides automatic memory zeroization, compile-time wordlist integrity verification, and comprehensive test coverage. Reference benchmarks on Apple M1 Pro (2021) demonstrate practical usability with 544 ms Standard mode and 2273 ms Paranoid mode single-layer derivations. Qatsi targets air-gapped systems and master credential generation where stateless reproducibility outweighs rotation flexibility.  \nKeywords: Key derivation, Argon2id, memory-hard functions, hierarchical derivation, stateless password management.  \n1 Introduction  \nPassword management architectures face a fundamental trade-off between security and usability. Centralized encrypted vaults (KeePassXC, Bitwarden) enable arbitrary credential storage and cross-device synchronization but concentrate risk in a single encrypted database. Vault compromise, cloud interception, or file exfiltration exposes all credentials. Deterministic generation eliminates persistent attack surfaces but sacrifices per-credential rotation and key isolation.  \nArgon2id, winner of the 2015 Password Hashing Competition [8] and standardized in RFC 9106 [1], remains underutilized in consumer password management despite its proven resistance to GPU/ASIC parallelization through memory-hardness. Mainstream alternatives like PBKDF2 (RFC 2898 [2]) lack memory-hard properties and remain vulnerable to hardware acceleration.  \nExisting deterministic schemes include Diceware [6] (physical dice, manual), BIP39 [7](PBKDF2-based, cryptocurrency wallets), and LessPass (stateless web passwords) . None provide  \n∗ Email: [contact@renecoignard.com](contact@renecoignard.com. ORCID:)[. ORCID:](contact@renecoignard.com. ORCID:) 0009-0004-0484-3336 †Email: anton .rygin@tu-dresden .de. ORCID: 0009-0009-3640-9872  \nhierarchical context-aware derivation with memory-hard KDF and provably uniform output sampling.  \nProblem. Generate cryptographically strong, reproducible secrets for master credentials (password manager master passwords, full-disk encryption passphrases, PGP/SSH key passphrases) without storing any persistent state, while resisting GPU attacks through memoryhardness.  \nContributions.  \n1. Hierarchical Argon2id chaining enabling context-specific derivation from a single master secret without storage overhead.  \n2. Formal proof of output uniformity via rejection sampling for both word-based (7776-word) and character-based (90-char) alphabets.  \n3. Quantitative GPU attack cost analysis with realistic hardware parameters showing ≈ 1016-year resistance for 80-bit entropy under 128 MiB memory constraints.  \n4. Production implementation in Rust with automatic zeroization, Unicode NFC normalization, and comprehensive testing including regression vectors verified on Apple M1 Pro hardware.  \nNon-goals. Qatsi does not replace traditional password managers for everyday website credentials with varying policies, existing passwords, or frequent ro","cbCaiu31G7JMTQPL","https://ap.wps.com/l/cbCaiu31G7JMTQPL","pdf",636976,"English","# Abstract\n# 1 Introduction\n## Password management trade-offs\n## Argon2id and related standards\n## Prior deterministic schemes and gap\n# Problem and contributions\n# 2 Related Work\n## 2.1 Memory-hard key derivation\n## 2.2 Deterministic password schemes","[{\"question\":\"What is Qatsi, and what core goal does it target?\",\"answer\":\"Qatsi is a hierarchical key-derivation scheme that generates reproducible cryptographic secrets without persistent storage. It targets high-stakes, stateless master credential generation where deterministic reproducibility outweighs rotation flexibility.\"},{\"question\":\"How does Qatsi resist attacks compared with traditional deterministic schemes?\",\"answer\":\"Qatsi uses Argon2id with memory-hard derivation, forcing attackers to allocate comparable memory per guess. It also applies hierarchical context layers derived deterministically from a single master secret.\"},{\"question\":\"What parameters and output formats does the paper report for entropy and usability?\",\"answer\":\"The paper reports 103–312 bits of entropy using memory-hard settings such as 64–128 MiB and 16–32 iterations. It supports word-based mnemonic outputs (7776-word set) and 90-character password outputs, with benchmarks reported on Apple M1 Pro for Standard and Paranoid modes.\"}]","Qatsi: Stateless Secret Generation via Hierarchical Memory-Hard Key Derivation | PDF",1791925587]