Android and iOS

Key versions and older encrypted data

Key lifecycles, signatures, encryption and application data.

Keys and cryptography1 min readEditorial methods

After rotation, the application must know which key opens existing data. Make version identity explicit in the format.

Evaluation approach

Map identifiers to trusted key records rather than arbitrary client-selected sources. Define old-key access periods.

Application example

An update can migrate old files through a controlled path to the new scheme.

Limits and considerations

Rotation does not automatically remove every copy of old data or keys.

Is a key identifier secret?

An identifier differs from key material, but must not redirect verification to an arbitrary source. Resolve known records under trusted acceptance policy.

Checks and decisions

  • Record versions
  • Test old data
  • Set retirement dates

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.