O buna perioada de timp am folosit StartCom (StartSSL), pentru ca erau gratuite si acceptate de browserele majore. Aparent au fost cumparati de WoSign, care se tine de practici necurate (backdating pentru a scoate certificate cu semnaturi SHA1).
https://blog.mozilla.org/security/2016/10/24/distrusting-new-wosign-and-startcom-certificates/
In alta ordine de idei, LetsEncrypt FTW.
PS: I loled: [Mozilla] No longer accept audits carried out by Ernst & Young Hong Kong.