Web Crypto API

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

The Web Crypto API is an interface allowing a script to use cryptographic primitives in order to build systems using cryptography.

Some browsers implemented an interface called Crypto without having it well defined or being cryptographically sound. In order to avoid confusion, methods and properties of this interface have been removed from browsers implementing the Web Crypto API, and all Web Crypto API methods are available on a new interface: SubtleCrypto. The Crypto.subtle property gives access to an object implementing it.

Warning: The Web Crypto API provides a number of low-level cryptographic primitives. It's very easy to misuse them, and the pitfalls involved can be very subtle.

Even assuming you use the basic cryptographic functions correctly, secure key management and overall security system design are extremely hard to get right, and are generally the domain of specialist security experts.

Errors in security system design and implementation can make the security of the system completely ineffective.

Please learn and experiment, but don't guarantee or imply the security of your work before an individual knowledgeable in this subject matter thoroughly reviews it. The Crypto 101 Course can be a great place to start learning about the design and implementation of secure systems.

Interfaces

Crypto

Provides basic cryptography features, such as a cryptographically strong random number generator, and access to cryptographic primitives via a SubtleCrypto object. An object of this type can be accessed in the global scope using Window.crypto or WorkerGlobalScope.crypto.

SubtleCrypto

Represents an object that provides low-level cryptographic functions for key generation, encryption, decryption, key wrapping and unwrapping, and so on.

CryptoKey

Represents a cryptographic key obtained from one of the SubtleCrypto methods generateKey(), deriveKey(), importKey(), or unwrapKey().

Dictionaries

AesCbcParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.encrypt(), SubtleCrypto.decrypt(), SubtleCrypto.wrapKey(), or SubtleCrypto.unwrapKey(), when using the AES-CBC algorithm.

AesCtrParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.encrypt(), SubtleCrypto.decrypt(), SubtleCrypto.wrapKey(), or SubtleCrypto.unwrapKey(), when using the AES-CTR algorithm.

AesGcmParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.encrypt(), SubtleCrypto.decrypt(), SubtleCrypto.wrapKey(), or SubtleCrypto.unwrapKey(), when using the AES-GCM algorithm.

AesParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.generateKey(), when generating an AES key: that is, when the algorithm is identified as any of AES-CBC, AES-CTR, AES-GCM, or AES-KW.

CryptoKeyPair

Represents a public and private key pair used for an asymmetric cryptography algorithm.

EcParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.generateKey(), when generating any elliptic-curve-based key pair: that is, when the algorithm is identified as either of ECDSA or ECDH.

EcKeyImportParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.importKey() or SubtleCrypto.unwrapKey(), when generating any elliptic-curve-based key pair: that is, when the algorithm is identified as either of ECDSA or ECDH.

EcdhKeyDeriveParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.deriveKey(), when using the ECDH algorithm.

EcdsaParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.sign() or SubtleCrypto.verify() when using the ECDSA algorithm.

HkdfParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.deriveKey(), when using the HKDF algorithm.

HmacImportParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.importKey() or SubtleCrypto.unwrapKey(), when generating a key for the HMAC algorithm.

HmacParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.generateKey(), when generating a key for the HMAC algorithm.

Pbkdf2Params

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.deriveKey(), when using the PBKDF2 algorithm.

RsaHashedImportParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.importKey() or SubtleCrypto.unwrapKey(), when importing any RSA-based key pair: that is, when the algorithm is identified as any of RSASSA-PKCS1-v1_5, RSA-PSS, or RSA-OAEP.

RsaHashedParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.generateKey(), when generating any RSA-based key pair: that is, when the algorithm is identified as any of RSASSA-PKCS1-v1_5, RSA-PSS, or RSA-OAEP.

RsaOaepParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.encrypt(), SubtleCrypto.decrypt(), SubtleCrypto.wrapKey(), or SubtleCrypto.unwrapKey(), when using the RSA_OAEP algorithm.

RsaPssParams

Represents the object that should be passed as the algorithm parameter into SubtleCrypto.sign() or SubtleCrypto.verify(), when using the RSA-PSS algorithm.

Extensions to other interfaces

Window.crypto

Represents the Crypto object associated with the global object in the main thread scope.

WorkerGlobalScope.crypto

Represents Crypto object associated with the global object in worker scope.

Specifications

Specification
Web Cryptography Level 2
# crypto-interface

Browser compatibility