ShieldZFS Extends ZFS to Detect Rollback and Fork Attacks by a Malicious Cloud Provider on TEE Storage

arXiv 2608.19924·medium signalXBlueskyLinkedInCopy link

Confidential computing protects code inside Trusted Execution Environments but leaves storage exposed: even with disk encryption a malicious provider can roll back, replay, fork or tamper with disk state, breaking freshness guarantees that stateful applications depend on. ShieldFS is a POSIX-compliant filesystem giving end-to-end integrity and freshness without application changes, representing permissible filesystem states as succinct cryptographic commitments held inside TEEs and replicated in a lightweight trusted registry, with an on-disk write-ahead log and storage pool authenticated by hash chains and an embedded Merkle tree. Implemented as an extension to ZFS, it verifies commitments on read so rollback and equivocation are detected even when the whole I/O stack is untrusted, at performance comparable to existing filesystems.