CAIN-42 CAIN StudioCGMS · Module 5 of 5 · 11 min
Provable deletion and retention
Erasure requests collide with tamper-evident storage: you must delete content but keep the chain verifiable. Tombstones solve this: the content is erased; a record that a deletion happened, and when, remains in the chain.
Set retention per memory class, and test that expired entries are actually removed from indexes and backups.
Prove deletion with evidence: the tombstone, the index state, the retention job's run record.
Key points
- Tombstones: erase content, keep proof.
- Retention per class; include indexes and backups.
- Prove deletion with records.
In the CAIN-42 codebase
cain-microservices/aether33/store.py— tombstoned deletes
Practice check
Practice 1 · true or false
“Tamper-evident storage makes erasure impossible.”
Practice 2 · choose one