Android and iOS

Digital signatures versus encryption

Key lifecycles, signatures, encryption and application data.

Keys and cryptography1 min readEditorial methods

A signature verifies approval by a key; encryption restricts reading. One does not imply the other.

Evaluation approach

Define signed data and context, and trust the source of verification keys.

Application example

A signed configuration file may remain readable. Adding a signature does not make embedded server secrets confidential.

Limits and considerations

A valid signature alone does not establish business correctness or freshness.

How is freshness established?

Old messages can retain valid signatures. Use time, sequence or challenge checks as the protocol requires. Integrity and freshness answer different questions.

Checks and decisions

  • Separate objectives
  • Define signature scope
  • Verify key provenance

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.