Sec-Private-State-Token-Crypto-Version header

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The HTTP Sec-Private-State-Token-Crypto-Version Fetch Metadata Request Header is used by the Private State Token API during token issuance to indicate to the issuer server which cryptographic protocol version should be used to sign blinded nonces when generating tokens.

At the time of writing, there is only one version supported, but this mechanism makes it possible to support multiple versions in the future.

Note that a developer wouldn't be expected to generate Sec-Private-State-Token-Crypto-Version request headers — these are created automatically by the browser when invoking private state token token-request fetch requests.

Header type Fetch Metadata Request Header
Forbidden request header Yes (Sec- prefix)
CORS-safelisted request header No

Syntax

http
Sec-Private-State-Token-Crypto-Version: <string>

Servers should ignore this header if it contains any other value.

Directives

<string>

A string containing the cryptographic protocol version that should be used by the issuer server to sign blinded nonces when generating tokens.

Examples

http
Sec-Private-State-Token-Crypto-Version: PrivateStateTokenV1VOPRF

Specifications

Specification
Private State Token API
# sec-private-state-token-crypto-version

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Sec-Private-State-Token-Crypto-Version
Experimental
Chrome – Full support
Chrome 117 (Release date: 2023-09-12)
footnote Full support
Edge – Full support
Edge 117 (Release date: 2023-09-15)
footnote Full support
Firefox – No support
Firefox
footnote No support
Opera – Full support
Opera 103 (Release date: 2023-10-03)
footnote Full support
Safari – No support
Safari
footnote No support
Chrome Android – Full support
Chrome Android 117 (Release date: 2023-09-12)
footnote Full support
Firefox for Android – No support
Firefox for Android
footnote No support
Opera Android – Full support
Opera Android 78 (Release date: 2023-10-23)
footnote Full support
Safari on iOS – No support
Safari on iOS
footnote No support
Samsung Internet – Full support
Samsung Internet 24 (Release date: 2024-01-25)
footnote Full support
WebView Android – No support
WebView Android
footnote No support
WebView on iOS – No support
WebView on iOS
footnote No support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.

See also