Window: crypto property

{{APIRef("Web Crypto API")}}

The crypto read-only property of the {{domxref("Window")}} interface returns the {{domxref("Crypto")}} object for this window's scope. This object gives 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, {{domxref("SubtleCrypto")}}) are not read-only, and therefore vulnerable to attack by {{glossary("polyfill")}}.

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

Value

An instance of the {{domxref("Crypto")}} interface, providing access to general-purpose cryptography and a strong random-number generator.

Examples

This example uses the crypto property to access the {{domxref("Crypto.getRandomValues", "getRandomValues()")}} method.

HTML

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

JavaScript

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

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

document.querySelector("button").addEventListener("click", genRandomNumbers);

Result

{{EmbedLiveSample('Examples')}}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• The {{domxref("Crypto")}} interface
• {{domxref("WorkerGlobalScope.crypto")}}