Android and iOS

What a file hash establishes

Key lifecycles, signatures, encryption and application data.

Keys and cryptography1 min readEditorial methods

Cryptographic hashes help compare files. An untrusted expected hash does not independently establish legitimacy.

Evaluation approach

Bind digests to controlled release records or verified manifests. Prevent unauthorized changes to both file and expected value.

Application example

CI can compare a delivered APK with the approved artifact record.

Limits and considerations

A hash provides neither file confidentiality nor suitable password protection by itself.

Where should expected hashes live?

Use controlled publication records. If one unauthorized change can replace both file and digest, the comparison cannot distinguish that change. Identify the trust source.

Checks and decisions

  • Protect expected values
  • Hash final packages
  • Keep purposes distinct

Sources

The primary references above provide the technical basis. Example workflows and evaluation suggestions are this publication’s explanations, not independent test results for a particular product.