Rotating Keys and Channel Safely

Approaches to Enhance Confidentiality with Cipher

While Cipher allows indefinite reuse of secure channels and keypairs, certain operational security practices can further enhance confidentiality, especially over time or in high-risk contexts.

Rotating Keypairs to Break Historical Linkage

We strongly recommend periodically rotating public/private keypairs for any individual conversation. This action effectively resets the encryption environment:

• Past encrypted exchanges become unreadable under the new keypair, even if intercepted.

• No cryptographic link persists between the old and new identity, assuming the old keypair is no longer used.

• Historical messages encrypted with previous keys remain sealed unless decrypted beforehand.

This offers maximum confidentiality for ongoing exchanges, particularly over long-term interactions.

Changing Structured Channels (Rarely Necessary)

While retaining the same structured channel is usually safe, users can rotate the structured channel itself if they suspect a compromise or wish to break cryptographic histories:

• Coordination is needed for new channel establishment, possibly involving secure regeneration or a Zero-Knowledge Proof-based transfer (see [Cross-Device Channel Handling]).

• The new channel must be memorized and constructed with equal rigor, as it's the only element never stored or transmitted.

Frequent channel changes are not advised unless necessary, as they do not significantly enhance security when keypairs are regularly rotated.

Summary

• Change keypairs regularly to break traceability and exposure from long-term use.

• Alter structured channels only in exceptional situations, such as suspected compromise.

Cipher supports both approaches seamlessly, without server dependency, metadata retention, or linkage across sessions.