Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am using Firefox 6.02 and Windows 7 x86 version. I was recently unable to log in to Gmail, Hotmail and other such websites. I checked the preferences and figured out there was some security issue as it only happened when websites shifted to HTTPS or secure logins. When I saw the browser options after checking time and date settings as they also invalidate secure certificates. I noticed that although SSL 3.0 was checked, how ever TLS 1.0 was not selected. I selected it and applied the option and now every thing worked out fine, however this was recent that Gmail etc stopped working before that the options were same and it worked.

I have two questions: What is TLS 1.0? and Why were Gmail and Hotmail not working before?

share|improve this question

TLS means Transport Layer Security, which is the newer version after Secure Sockets Layer (SSL).

These are basically only encryption algorithms that are invoked by using the Hypertext Transfer Protocol Secure (HTTPS), which happens one uses https: as the protocol while browsing.

Which version of TLS/SSL is used, is determined during the hand-shake between the secure website and the browser, with the intent of using the latest and most secure version of protocol that is supported by both.

By default, not all the protocols are turned on by Firefox, especially the ones that are depreciated or thought to be unsafe. Gmail and Hotmail should work with Firefox 6, but possibly some manipulation or an installed extension has toggled off the required protocol(s).

share|improve this answer
So does that mean that Gmail and Hotmail have shifted to TLS and left SSL v 3.0 ? – aibk01 Sep 28 '11 at 16:25
TLS is not new : The latest TLS 1.2 (SSL 3.3) was defined in August 2008. It is most likely something that changed on your computer without you noticing. If you could remember what you did at this date, like for example maybe upgrading to Firefox 6.02? – harrymc Sep 28 '11 at 16:54
Well upgrade was at a few days earlier than this! – aibk01 Sep 28 '11 at 16:55
If it is not the upgrade that did it, and you cannot remember any special action from this date, then the cause might remain a mystery forever, since most likely something turned it off. – harrymc Sep 28 '11 at 17:18
Is your computer managed by someone else? They may have turned off some of the (known poor) ciphers due to some recent buzz. It may have left you're SSL3 configured in a way the Goog won't tolerate. In any case you should have SSL2 off, any cipher with CBC in the name off, and TLS on... having SSL3 on is reasonable. Be sure to turn on revocation checking if it's not on (security -> advanced -> validation or something like that). – Ram Sep 28 '11 at 21:02

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.