@hpke/dhkem-secp256k1

A TypeScript Hybrid Public Key Encryption (HPKE) module extension for DH-KEM with secp256k1 curve, which is implemented by using @noble/curves/secp256k1. Note that the extension is EXPERIMENTAL and NOT STANDARDIZED.

Documentation: jsr.io | pages (only for the latest ver.)

Index

Installation
Usage
Contributing

Installation

@hpke/dhkem-secp256k1 need to be used with @hpke/core, which can be installed in the same manner as desribed below.

Node.js

You can install the package with npm, yarn or pnpm.

# Using npm:
npm install @hpke/dhkem-secp256k1
yarn add @hpke/dhkem-secp256k1
pnpm install @hpke/dhkem-secp256k1
# Using jsr:
npx jsr add @hpke/dhkem-secp256k1
yarn dlx jsr add @hpke/dhkem-secp256k1
pnpm dlx jsr add @hpke/dhkem-secp256k1

The above manner can be used with other JavaScript runtimes that support npm, such as Cloudflare Workers and Bun.

Then, you can use the module from code like this:

import { Aes128Gcm, CipherSuite, HkdfSha256 } from "@hpke/core";
import { DhkemSecp256k1HkdfSha256 } from "@hpke/dhkem-secp256k1";

Deno

For Deno, it is recommended to use the jsr.io registry.

deno add jsr:@hpke/dhkem-secp256k1

Web Browsers

Followings are how to use this module with typical CDNs. Other CDNs can be used as well.

Using esm.sh:

<!-- use a specific version -->
<script type="module">
  import {
    Aes128Gcm,
    CipherSuite,
    HkdfSha256,
  } from "https://esm.sh/@hpke/core@<SEMVER>";
  import {
    DhkemSecp256k1HkdfSha256,
  } from "https://esm.sh/@hpke/dhkem-secp256k1@<SEMVER>";
  // ...
</script>

<!-- use the latest stable version -->
<script type="module">
  import {
    Aes128Gcm,
    CipherSuite,
    HkdfSha256,
  } from "https://esm.sh/@hpke/core";
  import {
    DhkemSecp256k1HkdfSha256,
  } from "https://esm.sh/@hpke/dhkem-secp256k1";
  // ...
</script>

Using unpkg:

<!-- use a specific version -->
<script type="module">
  import {
    Aes128Gcm,
    CipherSuite,
    HkdfSha256,
  } from "https://unpkg.com/@hpke/core@<SEMVER>/esm/mod.js";
  import {
    DhkemSecp256k1HkdfSha256,
  } from "https://unpkg.com/@hpke/dhkem-secp256k1@<SEMVER>/esm/mod.js";
  // ...
</script>

Usage

This section shows some typical usage examples.

Node.js

import { Aes128Gcm, CipherSuite, HkdfSha256 } from "@hpke/core";
import { DhkemSecp256k1HkdfSha256 } from "@hpke/dhkem-secp256k1";
// const { DhkemSecp256k1HkdfSha256 } = require("@hpke/dhkem-secp256k1");

async function doHpke() {
  // setup
  const suite = new CipherSuite({
    kem: new DhkemSecp256k1HkdfSha256(),
    kdf: new HkdfSha256(),
    aead: new Aes128Gcm(),
  });

  const rkp = await suite.kem.generateKeyPair();

  const sender = await suite.createSenderContext({
    recipientPublicKey: rkp.publicKey,
  });

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("Hello world!"));

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp.privateKey,
    enc: sender.enc,
  });

  // decrypt
  const pt = await recipient.open(ct);

  // Hello world!
  console.log(new TextDecoder().decode(pt));
}

try {
  doHpke();
} catch (err) {
  console.log("failed:", err.message);
}

Deno

import { Aes128Gcm, CipherSuite, HkdfSha256 } from "@hpke/core";
import { DhkemSecp256k1HkdfSha256 } from "@hpke/dhkem-secp256k1";

async function doHpke() {
  // setup
  const suite = new CipherSuite({
    kem: new DhkemSecp256k1HkdfSha256(),
    kdf: new HkdfSha256(),
    aead: new Aes128Gcm(),
  });

  const rkp = await suite.kem.generateKeyPair();

  const sender = await suite.createSenderContext({
    recipientPublicKey: rkp.publicKey,
  });

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("Hello world!"));

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp.privateKey,
    enc: sender.enc,
  });

  // decrypt
  const pt = await recipient.open(ct);

  // Hello world!
  console.log(new TextDecoder().decode(pt));
}

try {
  doHpke();
} catch (_err: unknown) {
  console.log("failed.");
}

Browsers

<html>
  <head></head>
  <body>
    <script type="module">
      import {
        Aes128Gcm,
        CipherSuite,
        HkdfSha256,
      } from "https://esm.sh/@hpke/core";
      import { DhkemSecp256k1HkdfSha256 } from "https://esm.sh/@hpke/dhkem-secp256k1";

      globalThis.doHpke = async () => {
        try {
          const suite = new CipherSuite({
            kem: new DhkemSecp256k1HkdfSha256(),
            kdf: new HkdfSha256(),
            aead: new Aes128Gcm(),
          });

          const rkp = await suite.kem.generateKeyPair();

          const sender = await suite.createSenderContext({
            recipientPublicKey: rkp.publicKey,
          });

          // encrypt
          const ct = await sender.seal(new TextEncoder().encode("Hello world!"));

          const recipient = await suite.createRecipientContext({
            recipientKey: rkp.privateKey, // rkp (CryptoKeyPair) is also acceptable.
            enc: sender.enc,
          });

          // decrypt
          const pt = await recipient.open(ct);

          // Hello world!
          alert(new TextDecoder().decode(pt));
        } catch (err) {
          alert("failed:", err.message);
        }
      };
    </script>
    <button type="button" onclick="doHpke()">do HPKE</button>
  </body>
</html>

Contributing

We welcome all kind of contributions, filing issues, suggesting new features or sending PRs.