node-seal ·

node-seal is an ESM-first, WebAssembly-powered wrapper around the C++ Microsoft SEAL homomorphic encryption library, for TypeScript and JavaScript.

v7.0.0 is a breaking release. The custom JS wrapper layer was removed — the package now exposes the Emscripten-generated bindings directly. That makes the package ~96% smaller and faster, but it also means some imports and helper methods changed.

• WebAssembly: Fast, direct bindings to Microsoft SEAL
• ESM-first: Modern module layout, no bundling
• Node.js + browser + edge (CF Workers): Everything you need (JS glue, .wasm, and typings) is in the package, so you can run it anywhere WASM is allowed.
• Low-level, close to C++: Method names and types now map much more directly to SEAL

Currently aligned with Microsoft SEAL 4.1.2.

Table of Contents

• Installation
• Quick Start
• What Changed in v7
• Environment Notes
  • React Native
• Demo
• Usage
• Documentation
• Examples
• Benchmarking
• Caveats
• Contributing
• License

Installation

Install from npm:

npm install node-seal
# or
yarn add node-seal
# or
pnpm add node-seal

Because v7 is ESM-first and publishes the .wasm alongside the JS glue and TypeScript definitions, most modern bundlers can import it directly without extra configuration.

Quick Start

In v7, the default import gives you a factory; call it to get the SEAL runtime:

import SEAL from 'node-seal'

const seal = await SEAL()

Variants:

// recommended and default: throws on transparent ciphertexts
import SEAL from 'node-seal/throws'
const seal = await SEAL()

// allow transparent ciphertexts (only if you know you need this)
import SEAL from 'node-seal/allows'
const seal = await SEAL()

What Changed in v7?

See here.

Environment Notes

React Native

You could use something like the react-native-webassembly lib, but this has not been tested.

Demo

Go to the sandbox

This sandbox was built for users to experiment and learn how to use Microsoft SEAL featuring node-seal.

• Encryption Parameters: experiment with many settings to prototype a SEALContext.
• Keys: Create, download, upload Secret/Public Keys - even for Relinearization and Galois Keys.
• Variables: Create, download, upload PlainTexts or CipherTexts
• Functions: Create a list of HE functions to execute!
• Code Generation: After your experimentation is complete, generate working code to use!

Note: the sandbox targets an earlier version of node-seal, so generated code may need adjustments for v7.

Usage

Checkout the basics

Documentation

v7 doesn't have a dedicated documentation page. Instead, you refer to the C++ bindings for additional information. The best examples and explanations are found in Microsoft SEAL's repository.

View the docs from v6.0.3 and earlier here

Examples

Check out the Sandbox to try out HE operations and even generate example code. Just a heads-up: the sandbox was built against an older version of node-seal, so while the demos still work, the code it generates isn't compatible with v7.

If you'd rather read an example, take a look here.

For more exhaustive examples, view the tests.

Changes

For changes in this library, take a look here.

For changes in Microsoft SEAL, take a look at their list of changes.

Benchmarking

npm run seal:build:bench
npm run benchmark

See also: BENCHMARK.md.

Caveats

• Memory: saving large keys in the browser is expensive; try a different compression mode if you get OOMs.
• Manual cleanup: call .delete() or .deleteLater() on created objects to free C++ resources.

Contributing

See CONTRIBUTING.md.

License

node-seal is MIT licensed.