Clojure Crypto Landscape Research

Existing Clojure Libraries for 25519 Cryptography

caesium (lvh/caesium) — Most Mature, JVM-only

• Approach: jnr-ffi binding to libsodium
• Clojars: caesium/caesium "0.15.0"
• Coverage: secretbox, box (Curve25519), sign (Ed25519), password hashing (argon2), generic hashing (BLAKE2b), random bytes, AEAD, key exchange, Ristretto255
• Design: Maps libsodium's C namespaces directly to Clojure namespaces
• API style: Operates on byte arrays, returns byte arrays. Keypairs as {:public :secret} maps
• Limitation: JVM only, requires native libsodium installed
• Status: Active (~691 commits), Eclipse Public License

naclj (franks42/naclj) — Deprecated, JVM-only

• Approach: jnr-ffi to libsodium (similar to caesium)
• Design: Protocol-based with distinct record types per key type
• Key innovation: URN-based intrinsic key identifiers (urn:nacl:pk:ed25519:<base64url>)
• JOSE exploration: Design doc exploring JWK/JOSE representation of NaCl keys
• Status: Deprecated — README points to caesium

fluree.crypto — Best Existing cljc Example

• Clojars: fluree/crypto "4.0.0"
• Cross-platform: JVM + Node.js + browser
• Coverage: Ed25519 signatures, JWS (RFC 7515/8037), DID (did:key), SHA-256/512, AES
• Platform strategy: JVM uses Java 17+ native Ed25519; JS uses @noble/ed25519
• Supports: GraalVM native compilation, multiple encodings (hex, base64, base58)

buddy-sign — Most Popular Signing, JVM-only

• Coverage: JWS, JWT, JWE, and "compact" format (signs any Clojure type via nippy)
• Ed25519: Supported via :eddsa algorithm
• Limitation: JVM-only, no ClojureScript support

Other Notable Libraries

Library	Platform	Notes
hiredman/ed25519	JVM	Pure Clojure port of Python ed25519.py, proof-of-concept
geheimnis	cljc	AES/RSA/MD5 only — no 25519
hasch	cljc	Deterministic SHA-512 hashing of EDN values (canonical serialization)
tweetnacl-java	JVM	Pure Java NaCl port, no native deps
salty-coffee	JVM	Pure Java NaCl, Java 11+, zero deps
TweetNaCl.js	JS	Via npm, usable from ClojureScript

Platform Crypto Capabilities

Java (JVM)

Ed25519 Signatures (JEP 339, Java 15+):

KeyPairGenerator.getInstance("Ed25519")  // no init needed
Signature.getInstance("Ed25519")         // sign/verify
// Types: EdECPublicKey, EdECPrivateKey, EdECPoint

X25519 Key Agreement (JEP 324, Java 11+):

KeyPairGenerator kpg = KeyPairGenerator.getInstance("XDH");
kpg.initialize(new NamedParameterSpec("X25519"));
KeyAgreement.getInstance("XDH")  // Diffie-Hellman
// Types: XECPublicKey, XECPrivateKey

WebCrypto API (Browser/Node.js)

Ed25519 (all major browsers as of 2025):

await crypto.subtle.generateKey({ name: "Ed25519" }, true, ["sign", "verify"]);
await crypto.subtle.sign({ name: "Ed25519" }, privateKey, data);
await crypto.subtle.verify({ name: "Ed25519" }, publicKey, signature, data);

X25519 (all major browsers as of early 2025):

await crypto.subtle.generateKey({ name: "X25519" }, true, ["deriveKey", "deriveBits"]);
await crypto.subtle.deriveBits({ name: "X25519", public: theirKey }, myKey, 256);

Key consideration: WebCrypto is async-only (returns Promises).

Polyfill Libraries

• @noble/curves (paulmillr): Pure JS, audited, Ed25519 + X25519 + more
• @noble/ed25519: Focused Ed25519 implementation
• Both useful as fallback when WebCrypto unavailable

Key Gaps in the Ecosystem

No existing library combines all of:

1. cljc portability (JVM + ClojureScript)
2. Ed25519 + X25519 (signing + key exchange/encryption)
3. EDN-native message formats (not JSON/JWS)
4. Platform-native backends (Java JCA + WebCrypto, minimal external deps)

This is exactly the gap signet aims to fill.