Introduction

Certificate Transparency is a system for monitoring and auditing publicly-trusted SSL certificates. This website monitors Certificate Transparency log servers to check that they are behaving correctly.

Logs

Show:

Log URL Newest verified STH timestamp (UTC) Status Uptime
Akamai https://ct.akamai.com 2015-07-27 17:28:48 Ceased N/A
Certly https://log.certly.io 2016-04-30 17:59:42 Ceased N/A
CNNIC https://ctserver.cnnic.cn 2017-01-23 04:02:01 Good 98.94%
Comodo Dodo https://dodo.ct.comodo.com 2017-01-23 04:15:47 Good 95.51%
DigiCert https://ct1.digicert-ct.com/log 2017-01-22 16:00:17 Good 99.98%
GDCA https://ctlog.gdca.com.cn 2017-01-23 04:17:09 Warning 99.37%
GDCA (Legacy) https://ct.gdca.com.cn 2017-01-23 04:13:03 Warning 99.44%
Google Aviator https://ct.googleapis.com/aviator 2016-11-30 13:24:18 Frozen 99.98%
Google Daedalus https://ct.googleapis.com/daedalus 2017-01-23 03:55:22 Good 100.00%
Google Icarus https://ct.googleapis.com/icarus 2017-01-23 03:07:59 Good 100.00%
Google Pilot https://ct.googleapis.com/pilot 2017-01-23 03:39:05 Good 99.96%
Google Rocketeer https://ct.googleapis.com/rocketeer 2017-01-23 03:29:18 Good 99.99%
Google Skydiver https://ct.googleapis.com/skydiver 2017-01-23 03:53:55 Good 100.00%
Google Submariner https://ct.googleapis.com/submariner 2017-01-23 03:53:46 Good 100.00%
Google Test Tube https://ct.googleapis.com/testtube 2017-01-23 03:55:11 Good 100.00%
Izenpe https://ct.izenpe.com 2016-10-25 07:25:56 Ceased N/A
Izenpe Argi https://ct.izenpe.eus 2017-01-23 04:14:46 Good 99.99%
Izenpe Pilot https://ct.izenpe.com/pilot 2016-05-14 19:41:49 Ceased N/A
NORDUnet Flimsy https://flimsy.ct.nordu.net N/A Ceased N/A
NORDUnet Plausible https://plausible.ct.nordu.net 2017-01-23 04:12:46 Good 100.00%
PuChuangSiDa https://www.certificatetransparency.cn/ct 2017-01-23 04:10:17 Good 100.00%
SSLWatcher.com Alpha https://alpha.ctlogs.org N/A Ceased N/A
StartCom https://ct.startssl.com 2017-01-23 04:11:13 Good 99.52%
Symantec https://ct.ws.symantec.com 2017-01-23 01:00:04 Good 100.00%
Symantec Deneb https://deneb.ws.symantec.com 2017-01-23 01:00:00 Good 99.80%
Symantec Vega https://vega.ws.symantec.com 2017-01-23 01:00:00 Good 99.94%
Venafi https://ctlog.api.venafi.com 2017-01-23 02:36:10 Good 99.95%
WoSign https://ctlog.wosign.com 2017-01-23 03:45:18 Good 97.62%
WoSign (Legacy) https://ct.wosign.com 2016-04-14 03:22:46 Ceased N/A

The list of logs is also available in JSON format at /logs.json. The schema is identical to the schema used by the official log_list.json and all_logs_list.json files, with the following exceptions:

Monitors

Gossip is pulled from the following monitors:

Monitor URL
Chromium STHSets https://clients2.google.com/service/update2/crx
ct.x509.io https://ct.x509.io

The API endpoint at /ct/v1/sth-gossip partially implements the draft-linus-trans-gossip-ct-01 draft RFC - feel free to point your monitor at it. It returns all the Signed Tree Heads observed over the last hour, so there is little point in querying it more than every 30 minutes. In return, I'd appreciate being able to fetch gossip from your monitor - get in touch with me if you want to organise this.

Methodology

I've put up a page describing the methodology used by the monitor. If the monitor displays a warning or bad status for a log, you should read the methodology page before reporting it to the log operator (or even better, get in touch, as the web interface doesn't present all of the available data). In particular, the backend is hosted from a residential Internet connection and network outages may cause false positives.