Hashing

Hashing gives an artifact a compact cryptographic identity.

Basic concept

Artifact Bytes
      ↓
Hash Function
      ↓
Digest

A verification workflow can later calculate the digest again and compare it with the preserved expected value.

PowerShell example

Get-FileHash ".\artifact.json" -Algorithm SHA256

Representation matters

A hash is calculated over bytes.

That means these can change a hash even when a human considers the content equivalent:

• property ordering
• whitespace
• line endings
• character encoding
• serialization differences

For structured semantic state, DigiEmu therefore separates:

Raw Representation
       ↓
Canonicalization
       ↓
Stable Representation
       ↓
Hash

Hashing is not signing

A hash can detect change.

A digital signature adds a claim tied to control of a private key.

These are separate mechanisms.

Verification pattern

Preserved Hash
      │
      │ compare
      ▼
Computed Hash
      ↓
MATCH / MISMATCH

Developer rule

Never compare hashes from two systems unless both systems agree on the exact representation being hashed.

Next

Continue with Signatures →.