AISS — Agent Identity and Signature Standard

Cryptographic trust primitive for autonomous AI agents.

---

Quickstart

from aiss import AgentIdentity

agent = AgentIdentity.create()
event = agent.stamp("user_prompted", {"data": "hello"})
assert agent.verify(event)
print(event["hash"])   # tamper-evident proof

{
  "agent_id":   "3gFw2S1NT6dzo9vTPQ6JNWEwYFysZn8F",
  "event_type": "user_prompted",
  "payload":    { "data": "hello" },
  "signature":  "eA3oT793bV/hJnDX...",
  "hash":       "8b1cfab333041b26...",
  "timestamp":  1771845244
}

pip install aiss

---

Why AISS

AISS makes agent actions:

• verifiable — cryptographic proof of authorship
• portable — no infrastructure dependency
• tamper-evident — hash-chained, any modification is detectable
• post-quantum ready — Ed25519 + ML-DSA-65 hybrid (NIST FIPS 204)

---

Core concepts

Primitive	Description	RFC
Identity	Deterministic agent ID derived from public key	§5–6
Event chain	Signed, hash-linked, append-only history	§7–9
Fork resolution	Deterministic canonical chain selection	§10
A2A trust	Agent-to-agent handshake and co-signed events	§16

---

Profiles

Profile	Cryptography	Use case
AISS-1	Ed25519 · SHA-256 · RFC 8785	General interoperability
AISS-2	Ed25519 + ML-DSA-65 hybrid	Regulated environments · forward secrecy

---

Low-level API

Full control over keys, events, chain, memory, and exports.

from aiss import generate_keypair, derive_agent_id, stamp_event, verify_event
from aiss.memory import store_event, search_events
from aiss.exports import export_audit_chain

priv, pub  = generate_keypair()
agent_id   = derive_agent_id(pub)
event      = stamp_event(priv, agent_id, {"event_type": "action"})
verify_event(event, pub)

See docs/API.md for the full reference.

---

PCP stack

AISS      — identity · event chain · fork resolution · A2A   ← this package

Foundation layer for verifiable agent systems.

AISS defines the standard. Additional features may be available in specific implementations.

Reference implementation: PiQrypt (Python)

---

Compliance (indicative)

Framework	Control	AISS mechanism
EU AI Act Art. 12	Inviolable logging	Hash-chained signed events
SOC 2 CC6.6	Audit trail	AISS-1.0-AUDIT export
NIST AI RMF MEASURE 2.5	Traceability	Tamper-evident event history
GDPR Art. 5.1.f	Integrity	Fork detection + signatures
HIPAA §164.312	Audit controls	Immutable event chain

AISS provides the cryptographic mechanisms. Compliance depends on implementation. Non-normative mapping.

---

Tooling

Vigil — optional local monitoring interface.

aiss start    # → http://localhost:8421

Provides a local dashboard for agent activity, chain health, and VRS scoring.

---

Implementations

Reference: PiQrypt (Python)

Community: open — submit a PR to list yours. Requirements: pass all normative test vectors in vectors/, conform to SPEC.md.

---

Spec

• RFC v2.0 — full protocol specification
• CONFORMANCE.md — implementation matrix
• aiss-standard.org — landing page & playground
• GitHub

---

Contributing

Contributions welcome — spec improvements, test vectors, bug reports. See CONTRIBUTING.md.

---

License

MIT — see LICENSE.

IP Notice

Protocol concepts deposited via e-Soleau (INPI France): DSO2026006483 — 19 Feb 2026 · DSO2026009143 — 12 Mar 2026