Every state change in this service appends a link to a hash chain. The chain head is signed (Ed25519) into a checkpoint, and the checkpoint is timestamped by an external RFC 3161 authority. The database can be rewritten by whoever holds the service key — the timestamp and the signature cannot.
Chain entries
–
Chain intact
–
Checkpoint signature
–
External timestamp
–
Chain head
- Sequence
- –
- Head SHA-256
- –
- Signing public key
- –
- Generated
- –
Latest checkpoint
- Created
- –
- Covers
- –
- Signature
- –
checkpoint.json · checkpoint.tsr · raw data (JSON)
Verify offline
Anyone can check the checkpoint without trusting this server:
curl -sO https://signatures.ai-water.uk/ledger/checkpoint.json curl -sO https://signatures.ai-water.uk/ledger/checkpoint.tsr openssl ts -verify -in checkpoint.tsr -data checkpoint.json -CAfile tsa-cacert.pem -untrusted tsa-cert.pem