HTTPS is a cornerstone of privacy in the modern Web. The public key
infrastructure underlying HTTPS, however, is a frequent target of
attacks. We introduce LogPicker, a novel protocol for strengthening
the public key infrastructure of HTTPS. LogPicker enables a pool of
Certificate Transparency (CT) logs to collaborate, where a randomly
selected log includes the certificate while the rest witness and
testify the certificate issuance process. As a result, CT logs
become capable of auditing the log in charge independently without
the need for a trusted third party.