Magic Number
A characteristic byte sequence at a known offset used to identify a file format or data structure independently of its filename extension.
Digital-Forensics Context
A magic number is a characteristic byte pattern, often at a defined offset, that helps identify a file format independently of its filename extension. File carving and content-based type detection use such signatures for formats including PNG, JPEG, ELF, and many proprietary structures.
Evidence Boundary
A matching header does not prove that a file is complete, valid, or safe. Truncated objects, forged headers, and polyglot files can satisfy a simple signature test while violating the expected format elsewhere.
Related Digital-Forensics Concepts
- File Carving
- File Format
- Binary Parsing
- Content Type