SoK: Cryptographic Key Recovery for Cryptoasset Custody and Financial Technologies

2026-08-07

AI Summary

This study addresses the critical vulnerability of cryptographic assets—loss or exposure of private keys leading to irreversible fund loss—and the absence of a coherent framework for comparing existing recovery mechanisms, which suffer from terminological inconsistency. Through a systematic literature review of 118 papers, the authors conduct qualitative coding to construct a primary matrix encompassing recovery targets, semantics, and mechanisms. They propose, for the first time, a five-category taxonomy grounded in recovery objectives: secret reconstruction, hybrid approaches, control restoration, forensic extraction, and framework-oriented recovery, thereby revealing the multidimensional nature of key recovery. Integrating perspectives from cryptography, distributed systems, and human-computer interaction, the work distills a generic construction model, identifies six key insights—including semantic heterogeneity, trust transference, and abuse pathways—and outlines a research agenda for recovery-aware financial technologies.

Abstract

Cryptoasset systems often bind cryptographic key control to financial control: losing a wallet seed, custody share, hardware device, or smart-account credential can remove spend authority, while compromised recovery can enable theft. Existing work treats recovery through separate vocabularies--key backup, secret sharing, account recovery, credential re-issuance, social recovery, and asset migration--making mechanisms and tradeoffs difficult to compare. This paper presents a Systematization of Knowledge (SoK) on cryptographic key recovery for cryptoasset custody and financial technologies. Starting from a 118-paper systematic-review discovery corpus, we derive a 77-paper synthesis corpus and code each retained system in a master matrix covering recovered objects, recovery semantics, mechanisms, enrollment and storage, authorization, trust placement, failure events, post-recovery state, validation evidence, deployment status, privacy, usability, and limitations. The matrix supports an axis-first taxonomy that separates secret-restoring, hybrid, control-restoring, forensic/extractive, and framework-oriented recovery. Our central observation is that recovery is not a single operation: systems may reconstruct an original secret, regenerate a seed, restore a share, reissue a credential, migrate signing authority, restore account control, move assets, or extract forensic artifacts. We derive a generalized construction model, check it against production-facing designs, and identify six findings: recovery semantics are heterogeneous; recovery shifts trust; liveness improvements create abuse paths; post-recovery lifecycle management is uneven; protocol evidence outpaces user evidence; and recovery metadata remains underprotected. These gaps motivate a research agenda for recovery-aware financial technologies.

Problem

• key recovery
• cryptoasset custody
• financial technologies
• secret sharing
• account recovery

Innovation

• Systematization of Knowledge
• cryptographic key recovery
• cryptoasset custody
• recovery semantics
• trust model