How CT fits into the wider Web PKI ecosystem

The systems we have seen so far are closed systems for which we have assumed that all the participants are trustworthy. But in an open system like the Web where anyone can take part, and there is no universally trusted authority, trust and security are top-level issues to address. Certificate Transparency is one approach to ensuring trust and improving security on the Web.

Security research on SSL certificate vulnerabilities where valid certificates outlive domain ownership, creating potential attack vectors for domain re-registration.