Question: OCSP stapling decreases the load on a PKI infrastructure's OCSP server by attaching a signed OCSP response to the target in a TLS connection. In addition it creates a more secure/private session since the CA doesn't know that your browser is accessing a given site. Some people have compared this behavior to Kerberos.

**Question**

* What web browsers support OCSP stapling?
* Are there any implementation considerations among different browsers that need to be addressed to maintain uniform privacy and performance benefits?

Answer: 
My impression is that [OCSP stapling is not well supported on the client side](https://web.archive.org/web/20151017004901/https://blogs.msdn.com/b/ieinternals/archive/2011/04/07/10151106.aspx?Redirected=true), but it's possible my information might be out of date.

Firefox apparently supports OCSP stapling, as of Firefox 26. (Thanks to Jan Schejbal for this information.)

Chrome supports OCSP stapling [on Windows, Linux, and ChromeOS](https://web.archive.org/web/20151216040743/https://code.google.com/p/chromium/issues/detail?id=361230#c8). (Thanks to Kit Sunde for this information.) (The Chrome team has [decided](https://arstechnica.com/information-technology/2012/02/google-strips-chrome-of-ssl-revocation-checking/) that they plan to [remove CRL and regular OCSP checks](https://www.imperialviolet.org/2012/02/05/crlsets.html), but they haven't disabled OCSP stapling.)

I've read one report that [most browsers support OCSP stapling on Windows](https://news.netcraft.com/archives/2013/07/19/microsoft-achieves-world-domination-in-ocsp-stapling.html).

Here is some more information on [browser support for OCSP](https://web.archive.org/web/20220307083919/http://www.carbonwind.net/blog/post/Random-SSLTLS-101-OCSPCRL-in-practice.aspx) (but not OCSP stapling, unfortunately).
Even with OCSP stapling, the act of verifying the OCSP signature may expose personal information to the OCSP signing root. Additionally the OCSP singing root can be a 3rd party to the entire infrastructure as shown here:

![PKI hierarchy with two roots](https://i.stack.imgur.com/T0ESx.gif)

[source](http://technet.microsoft.com/en-us/library/ee619784%28v=ws.10%29)

Although there are security benefits to validating the signing OCSP signature, if privacy concerns outweigh security the following extension disables the signing functionality `szOID_PKIX_OCSP_NOCHECK (1.3.6.1.5.5.7.48.1.5)` (note it is up to the CA to implement this extension)

If you want to use CRL instead of OCSP, you can set the following setting to 1 or zero on a Windows machine

```
 HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\SystemCertificates\ChainEngine\Config\CryptnetCachedOcspSwitchToCrlCount

```