Key Types

ATP supports multiple cryptographic key types for flexibility and future-proofing.

Supported Types

Type	Algorithm	Quantum Safe	Status
gpg	GPG (any)	❌	Stable
ed25519	Ed25519	❌	Recommended
secp256k1	secp256k1	❌	Interop only
dilithium	ML-DSA (Dilithium)	✅	Experimental
falcon	FALCON	✅	Experimental

Ed25519 (Recommended)

The default choice for new agents:

• Fast — 20-30x faster than secp256k1
• Compact — 32-byte keys, 64-byte signatures
• Secure — Side-channel resistant by design
• Deterministic — No RNG needed for signing

const nacl = require('tweetnacl');
const keyPair = nacl.sign.keyPair();
// keyPair.publicKey = 32 bytes
// keyPair.secretKey = 64 bytes

GPG

For agents with existing GPG keys:

• Supports RSA, DSA, ECDSA, EdDSA
• Uses standard GPG fingerprint (SHA-1)
• Wide tooling support

gpg --full-generate-key
gpg --list-keys --keyid-format long

secp256k1

Only for Bitcoin/Ethereum interop:

• Same curve as Bitcoin/Nostr
• Use Schnorr signatures (BIP-340)
• Not recommended for new agents — poor implementations common

Post-Quantum (Dilithium, FALCON)

Reserved for quantum resistance:

• ML-DSA (Dilithium) — NIST FIPS 204, larger signatures (~2.4KB)
• FALCON — Smaller signatures (~666 bytes), complex implementation

Use SHA-384 fingerprints for 192-bit quantum security.

WARNING

Post-quantum support is draft. Wait for ecosystem maturity before deploying.

Choosing a Key Type

Need PQ safety now?
├─ Yes → Dilithium (hybrid with Ed25519 recommended)
└─ No → Ed25519

Have existing GPG key?
├─ Yes → GPG is fine
└─ No → Ed25519

Need Bitcoin interop?
├─ Yes → secp256k1
└─ No → Ed25519