Cryptography and key management policy

Encryption#

1. In transit: TLS 1.2 or higher on every external connection and every connection that leaves a host (database replicas, backups, vendor APIs). HSTS on every public hostname ACC-12.
2. At rest: production disks, databases, object storage and backups are encrypted with AES-256 or the provider's equivalent ACC-11. Backups are encrypted before they leave the host, with a key not stored beside them.
3. P0 fields additionally use application-level encryption with a separate key where the playbook requires it.
4. Algorithms: use the platform's standard libraries. No custom cryptography. Passwords use argon2id or bcrypt. Tokens stored at rest are hashed (SHA-256 or better) where only comparison is needed.
5. Claims: do not describe anything as end-to-end encrypted or zero-knowledge unless it is (red line 1).

Secrets#

1. Secrets live in [the secrets manager], or in environment files with mode 600 owned by the service user, or in systemd credentials. Never in git, container images, logs, tickets, chat, or AI prompts ACC-13.
2. Secret scanning runs on every push and blocks a commit that contains one.
3. Each secret has an owner and a rotation date in the secrets inventory.
4. A secret that has ever been committed to git, pasted into a chat or an AI session, printed to a log, or held by someone who has left is exposed and is rotated within 24 hours. Removing it from git history is not a substitute for rotation.

Rotation schedule#

Every rotation is logged with date, secret name (not value) and person ACC-14.