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crypto global property

The global read-only crypto property returns the Crypto object associated to the global object. This object allows web pages access to certain cryptographic related services.

Although the property itself is read-only, all of its methods (and the methods of its child object, SubtleCrypto) are not read-only, and therefore vulnerable to attack by polyfill.

Although crypto is available on all windows, the returned Crypto object only has one usable feature in insecure contexts: the getRandomValues() method. In general, you should use this API only in secure contexts.

Value

An instance of the Crypto interface, providing access to general-purpose cryptography and a strong random-number generator.

Examples

This example uses the crypto property to access the getRandomValues() method.

JavaScript

globalThis.genRandomNumbers = () => {
  const array = new Uint32Array(10);
  crypto.getRandomValues(array);

  const randText = document.getElementById("myRandText");
  randText.textContent = `The random numbers are: ${array.join(" ")}`;
};

HTML

html

<p id="myRandText">The random numbers are:</p>
<button type="button" onClick="genRandomNumbers()">
  Generate 10 random numbers
</button>

Result

Specifications

Specification
Web Cryptography API # dom-windoworworkerglobalscope-crypto

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`crypto_property`	37	12	1	11	24	5	37	37	4	24	5	3.0
`worker_support`	37	79	48	No	24	10.1	37	37	48	24	10.3	3.0