MD5 Checksum

Overview

An MD5 checksum is a digest computed from file bytes. If the file changes—even by one bit—the digest changes, allowing archives to detect corruption or copy errors. While MD5 is cryptographically broken against deliberate attack, it remains common for integrity checks in media workflows where the threat is accidental drift, not malicious tampering.

Use in Preservation

Upon creating a DPX/TIFF sequence, systems compute per-file checksums and a manifest. During transfers (ingest → SAN → LTO), software re-computes and compares digests, flagging mismatches. Scheduled fixity audits re-hash stored files to catch latent errors.

Alternatives and Policy

SHA-256/512 provide stronger properties with modest performance cost; many institutions are migrating to them for future-proofing. Policies may record both MD5 and SHA-256 to bridge legacy tools and modern expectations.

Operational Tips

Normalize line endings and metadata handling so manifests are stable across platforms. Store manifests alongside the content and in a catalog database. When verifying sequences, log failures with exact paths and reel IDs to accelerate repair.

Related Terms

• Bit rot, fixity audit, LTO tape, digital preservation master.