expo-crypto

Open Beta Documentation Amazon offers this technical documentation as part of a pre-release, open beta. The features described might change as Amazon receives feedback and iterates on the features. For the most current feature information, see the latest Release Notes.

@amazon-devices/expo-crypto is a universal library for crypto operations that enables you to hash data in an equivalent manner to the Node.js core crypto API.

Installation
Examples
API reference
- Methods
Supported versions
Related topics

Installation

Add the JavaScript library dependency in the package.json file.

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 dependencies: {
     ...
     "@amazon-devices/expo-crypto": "~2.0.1",
     "@amazon-devices/keplerscript-turbomodule-api": "~1.0.0",
     ...
 }

Reinstall dependencies using the npm install command.

Examples

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import React, {useEffect, useState} from 'react';
import {StyleSheet, View, Text} from 'react-native';
import * as Crypto from '@amazon-devices/expo-crypto';

export const App = () => {
  const [digest, setDigest] = useState<string>();

  useEffect(() => {
    (async () => {
      const digestStr = await Crypto.digestStringAsync(
        Crypto.CryptoDigestAlgorithm.SHA256,
        'GitHub stars are neat 🌟',
      );
      setDigest(digestStr);
    })();
  }, []);

  return (
    <View style={styles.container}>
      <Text style={styles.text}>Crypto Module Example {digest}</Text>
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'white',
    justifyContent: 'center',
    alignItems: 'center',
  },
  text: {
    fontSize: 30,
    color: 'black',
  },
});

API reference

See the dedicated documentation page for information about this library and API reference: Official Expo documentation for expo-crypto.

Methods

Method	Description	Supported
`digest`	Get a hash from a passed array buffer (or array buffer view)	✅ Yes
`digestStringAsync`	Get a hash from a passed string	✅ Yes
`getRandomBytes`	Get an array buffer filled with random values	✅ Yes
`getRandomBytesAsync`	Get an array buffer filled with random values	✅ Yes
`getRandomValues`	Fill an array buffer with random values	✅ Yes
`randomUUID`	Generate a random UUID	✅ Yes
`CryptoDigestAlgorithm`	Enum for the Expo Crypto library.	✅ Yes
`MD2`	The one unsupported method from the `CryptoDigestAlgorithm` library.	❌ No

Supported versions

Package Version	Based On	@amazon-devices/react-native-kepler version
2.0.x	12.7.0	2.0.x

Supported Third-Party Libraries and Services.

Last updated: Sep 30, 2025