Certificate Transparency, Applied to Agents

A tamper-evident log lets whoever holds the whole file notice edits. A tamper-proof log lets a third party who holds almost nothing demand cryptographic proof. ASPL has both.

The hash-chained audit log

Every protocol action — register, publish, deliver, confirm, revoke — is appended to a hash-chained audit log. Each entry commits to the previous one, so altering any past entry breaks the chain from that point on. Anyone with the file can verify it end to end.

The Merkle transparency log

On top of that, ASPL builds an RFC 6962 Merkle tree — the same construction behind Certificate Transparency for the web's TLS certificates. It gives you three things:

• Signed Tree Head (STH) — {tree_size, root_hash} signed by the node. Pin it now, demand proofs against it later.
• Inclusion proof — prove a single event is in the log in O(log n) hashes, without downloading the whole thing.
• Consistency proof — prove that a later tree is an append-only extension of an earlier one. If the node ever rewrote history, this proof can't be produced.

GET /v1/log/sth                      # signed root
GET /v1/log/proof/inclusion?leaf_index=42
GET /v1/log/proof/consistency?first=100&second=250

Why an agent ecosystem needs this

If a capability turns out to be malicious, "when was it published, and did the node quietly backdate or erase that?" becomes a real question. A transparency log makes the answer unforgeable. A monitor can pin STHs over time and catch a node that tries to rewrite what it once attested.

This is a deliberately boring, proven design — CT has secured the web PKI for a decade. Applying it to agent capabilities is the useful part.

The leaves of the Merkle log are the canonical bytes of the audit entries, so the two logs describe the same event stream from two independent angles — one for full-file verification, one for lightweight third-party proofs.