Why Immutable Backups and Content-Defined Chunking Beat Ransomware

Ransomware attackers no longer just encrypt live server filesystems; they actively seek out, corrupt, and delete backup repositories to force victim payouts.

To build genuine data resilience, modern backup architectures must be cryptographically immutable. In dewDrive, backups are modeled using Content-Defined Chunking (CDC) and Merkle tree structures powered by Restic and Kopia engines.

When a snapshot is committed, chunks are indexed by their cryptographic hashes (SHA-256 / BLAKE2b). The directory index tree forms an append-only graph. Previous snapshots can never be mutated by a running agent.

Furthermore, when paired with S3 Object Lock (Compliance/Governance mode) or WORM storage policies on Wasabi and Backblaze B2, even a compromised administrator credential cannot delete historical snapshot blocks until their retention retention window expires.

By decoupling your backup storage from proprietary vendors and storing end-to-end encrypted blocks in your own S3 vault, you retain 100% data sovereignty.