sd_jwt

December 17, 2025 ยท View on GitHub

A Rust implementation of RFC 9901 - Selective Disclosure for JSON Web Tokens (SD-JWT).

SD-JWT allows an issuer to create a JWT where some claims can be selectively disclosed by the holder. This enables privacy-preserving use cases where only necessary information is revealed to verifiers.

Features

  • RFC 9901 compliant - Full implementation of the SD-JWT specification
  • Selective disclosure - Mark specific claims as selectively disclosable
  • Array element disclosure - Support for disclosing individual array elements
  • Decoy digests - Add decoy digests for enhanced privacy
  • Key binding - Support for holder key binding with KB-JWT
  • Multiple hash algorithms - SHA-256, SHA-384, SHA-512

Quick Start

use sd_jwt::{
    issuer::issue_sd_jwt,
    holder::HolderSdJwt,
    verifier::verify_sd_jwt,
    types::SdJwtConfig,
};
use serde_json::json;

// Issuer creates an SD-JWT
let claims = json!({
    "sub": "user123",
    "given_name": "John",
    "family_name": "Doe",
    "email": "john@example.com"
});

let issued = issue_sd_jwt(
    &issuer_private_key,
    "https://issuer.example.com",
    claims,
    &["given_name", "family_name", "email"],  // Selectively disclosable
    &SdJwtConfig::default(),
    None,
    None,
).unwrap();

// Holder creates a presentation (disclosing only given_name)
let holder_jwt = HolderSdJwt::parse(&issued.serialized).unwrap();
let presentation = holder_jwt.create_presentation(&["given_name"]).unwrap();

// Verifier verifies the presentation
let verified = verify_sd_jwt(
    &presentation.serialize(),
    &issuer_public_key,
    "https://issuer.example.com",
).unwrap();

// Only "given_name" is disclosed, other SD claims are hidden
assert_eq!(verified.get("given_name").unwrap(), "John");
assert!(verified.get("email").is_none());

SD-JWT Format

Per RFC 9901, the SD-JWT format uses ~ as the separator:

<Issuer-signed JWT>~<Disclosure 1>~<Disclosure 2>~...~<Disclosure N>~

With Key Binding:

<Issuer-signed JWT>~<Disclosure 1>~...~<Disclosure N>~<KB-JWT>

Modules

  • issuer - Functions for creating SD-JWTs
  • holder - Functions for creating presentations with selected disclosures
  • verifier - Functions for verifying SD-JWT presentations
  • disclosure - Disclosure data structure and utilities
  • types - Core types (SdJwt, SdJwtKb, configuration, etc.)

Examples

See the examples/ directory for complete examples:

cargo run --example rfc9901_example

Legacy API

The library also includes the legacy API from the draft-02 implementation for backward compatibility. New code should use the RFC 9901 compliant API.

License

Licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.