> In principle, everybody who sees the log could agree that they see the same Merkle Tree head, thus the certificate really is logged. In practice the mechanism

> In principle, everybody who sees the log could agree that they see the same Merkle Tree head, thus the certificate really is logged. In practice the mechanisms to ensure this works, a Gossip protocol, do not exist and have never been deployed in practical use. It has been - the commercial instance of Cert Spotter gossips STHs with Chrome's SCT auditing infrastructure. Edit: here's the gossip feed of STHs observed by Chrome's SCT auditing infrastructure: https://www.gstatic.com/ct/gossip/ct/v1/sth-pollination https://www.gstatic.com/ct/gossip/ct/v1/sth-pollination And here's the gossip feed of STHs observed by Cert Spotter: https://certspotter.com/.well-known/ct/v1/sth-pollination https://certspotter.com/.well-known/ct/v1/sth-pollination