The read-only Window.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 window.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.
Syntax
var cryptoObj = window.crypto || window.msCrypto; // for IE 11
Value
An instance of the Crypto
interface, providing access to general-purpose cryptography and a strong random-number generator.
Example
This example uses the Window.crypto
property to access the getRandomValues()
method.
JavaScript
genRandomNumbers = function getRandomNumbers() { var array = new Uint32Array(10); window.crypto.getRandomValues(array); var randText = document.getElementById("myRandText"); randText.innerHTML = "The random numbers are: " for (var i = 0; i < array.length; i++) { randText.innerHTML += array[i] + " "; } }
HTML
<p id="myRandText">The random numbers are: </p> <button type="button" onClick='genRandomNumbers()'>Generate 10 random numbers</button>
Result
Specifications
Specification | Status | Comment |
---|---|---|
Web Cryptography API The definition of 'Window.crypto' in that specification. |
Recommendation | Initial definition |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
crypto | Chrome Full support 37 | Edge Full support 12 | Firefox Full support 34 | IE
Full support
11
| Opera Full support 24 | Safari Full support 6.1 | WebView Android Full support 37 | Chrome Android Full support 37 | Firefox Android Full support 34 | Opera Android Full support 24 | Safari iOS Full support 6.1 | Samsung Internet Android Full support 3.0 |
Legend
- Full support
- Full support
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.