Did you had the following error lately trying to open a SSL Web site with Firefox?
Error ssl_error_weak_server_ephemeral_dh_key
This is because the remote Web server is using the weak SSLv3 protocol. The only way to get to the site would be disabling this SSLv3 check in Firefox. However do only if you know what you are doing!
1. Open the Firefox advanced configuration :
about:config
2. Search for the following parameters :
security.ssl3.dhe_rsa_aes_128_sha security.ssl3.dhe_rsa_aes_256_sha
3. Double click on those items to disable the check.