Known Logs

This page contains details of the currently known CT Logs.

The list of CT logs that are currently compliant with Chrome's CT policy (or have been and were disqualified) is available in a machine-readable (JSON) format at:

log_list.json is signed by Google, the signature being hosted at:

The public key to verify log_list.sig can be found at:

The list of CT all known and announced logs is available in a machine-readable (JSON) format at:

Both log_list.json and all_logs_list.json conform with the following schema:


Active Logs


ct.googleapis.com/pilot

Base64 Log ID: pLkJkLQYWBSHuxOizGdwCjw1mAT5G9+443fNDsgN3BA=
Operator: Google
Started: 2013-03-25
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: google-ct-logs@googlegroups.com
Chrome inclusion status: Included.

ct.googleapis.com/icarus

Base64 Log ID: KTxRllTIOWW6qlD8WAfUt2+/WHopctykwwz05UVH9Hg=
Operator: Google
Started: 2016-07-27
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: google-ct-logs@googlegroups.com
Chrome inclusion status: Included (since M55).
Notes: Accepts only certificates issued by Let's Encrypt or other subordinate CAs signed by IdenTrust DST X3.

ct.googleapis.com/rocketeer

Base64 Log ID: 7ku9t3XOYLrhQmkfq+GeZqMPfl+wctiDAMR7iXqo/cs=
Operator: Google
Started: 2014-09-01
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: google-ct-logs@googlegroups.com
Chrome inclusion status: Included (since M43).

ct.googleapis.com/skydiver

Base64 Log ID: u9nfvB+KcbWTlCOXqpJ7RzhXlQqrUugakJZkNo4e0YU=
Operator: Google
Started: 2016-06-10
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: google-ct-logs@googlegroups.com
Chrome inclusion status: Included (since M55).
Notes: Does not accept certificates issued by Let's Encrypt or other subordinate CAs signed by IdenTrust DST X3.

ct1.digicert-ct.com/log

Base64 Log ID: VhQGmi/XwuzT9eG9RLI+x0Z2ubyZEVzA75SYVdaJ0N0=
Operator: DigiCert
Submitted for inclusion in Chrome: 2014-09-30
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ctops@digicert.com
Chrome inclusion status: Included.

ct.ws.symantec.com

Base64 Log ID: 3esdK3oNT6Ygi4GtgWhwfi6OnQHVXIiNPRHEzbbsvsw=
Operator: Symantec
Submitted for inclusion in Chrome: 2015-05-1
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: DL-ENG-Symantec-CT-Log@symantec.com
Chrome inclusion status: Included (since M45).

vega.ws.symantec.com

Base64 Log ID: vHjh38X2PGhGSTNNoQ+hXwl5aSAJwIG08/aRfz7ZuKU=
Operator: Symantec
Submitted for inclusion in Chrome: 2015-11-13
HTTPS supported: yes
MMD: 24 hours
Contact: DL-ENG-Symantec-VEGA-CT-Log@symantec.com; +1 (650) 527-466
Chrome inclusion status: Included (since M50).

ctlog.api.venafi.com

Base64 Log ID: rDua7X+pZ0dXFZ5tfVdWcvnZgQCUHpve/+yhMTt1eC0=
Operator: Venafi
Submitted for inclusion in Chrome: 2015-06-11
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ctlog-admin@venafi.com
Chrome inclusion status: Included (since M47).

ctlog.wosign.com

Base64 Log ID: QbLcLonmPOSvG6e7Kb9oxt7m+fHMBH4w3/rjs7olkmM=
Operator: WoSign
Submitted for inclusion in Chrome: 2016-04-19
HTTPS supported: yes
MMD: 24 hours
Contact: ctlog@wosign.com; +86-755-8600 8688
Chrome inclusion status: Included (since M54).

ctlog2.wosign.com

Base64 Log ID: Y9AAYCbd4QuwYB9FJEaWXuK26izU+8layGalUK+Qdbc=
Operator: WoSign
Submitted for inclusion in Chrome: 2017-05-03
HTTPS supported: yes
MMD: 24 hours
Contact: ctlog@wosign.com; +86-755-8600 8688
Chrome inclusion status: Pending inclusion.

ctserver.cnnic.cn

Base64 Log ID: pXesnO11SN2PAltnokEInfhuD0duwgPC7L7bGF8oJjg=
Operator: CNNIC
Submitted for inclusion in Chrome: 2016-02-02
HTTPS supported: yes
MMD: 24 hours
Contact: ctlog-admin@cnnic.cn; +86 (010) 58813200
Chrome inclusion status: Included (since M53).

ct.startssl.com

Base64 Log ID: NLtq1sPfnAPuqKSZ/3iRSGydXlysktAfe/0bzhnbSO8=
Operator: StartCom
Submitted for inclusion in Chrome: 2016-05-13
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ct@startssl.com
Chrome inclusion status: Included (since M54).

ct.izenpe.eus

Base64 Log ID: iUFEnHB0Lga5/JznsRa6ACSqNtWa9E8CBEBPAPfqhWY=
Operator: Izenpe
Submitted for inclusion in Chrome: 2016-05-24
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: atecnica@izenpe.net
Chrome inclusion status: Applied for inclusion but did not qualify.

ct.gdca.com.cn

Base64 Log ID: yc+JCiEQnGZswXo+0GXJMNDgE1qf66ha8UIQuAckIao=
Operator: Wang Shengnan
Submitted for inclusion in Chrome: 2016-04-07
HTTPS supported: yes
MMD: 24 hours
Contact: capoc@gdca.com.cn; +86 (20) 83487228-805
Chrome inclusion status: Applied for inclusion but did not qualify.

ctlog.gdca.com.cn

Base64 Log ID: kkow+Qkzb/Q11pk6EKx1osZBco5/wtZZrmGI/61AzgE=
Operator: GDCA
Submitted for inclusion in Chrome: 2016-10-10
HTTPS supported: yes
MMD: 24 hours
Contact: capoc@gdca.com.cn; +86 (20) 83487228-805
Chrome inclusion status: Applied for inclusion but did not qualify.

ctlog-gen2.api.venafi.com

Base64 Log ID: AwGd8/2FppqOvR+sxtqbpz5Gl3T+d/V5/FoIuDKMHWs=
Operator: Venafi
Submitted for inclusion in Chrome: 2017-02-03
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ctlog-admin@venafi.com
Chrome inclusion status: Pending inclusion.

sirius.ws.symantec.com

Base64 Log ID: FZcEiNe5l6Bb61JRKt7o0ui0oxZSZBIan6v71fha2T8=
Operator: Symantec
Submitted for inclusion in Chrome: 2017-02-15
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: DL-ENG-Symantec-SIRIUS-CT-Log@symantec.com
Chrome inclusion status: Included (since M60).


ct2.digicert-ct.com/log

Base64 Log ID: h3W/51l8+IxDmV+9827/Vo1HVjb/SrVgwbTq/16ggw8=
Operator: DigiCert
Submitted for inclusion in Chrome: 2017-03-03
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ctops@digicert.com
Chrome inclusion status: Included (since M60).


mammoth.ct.comodo.com

Base64 Log ID: b1N2rDHwMRnYmQCkURX/dxUcEdkCwQApBo2yCJo32RM=
Operator: Comodo
Submitted for inclusion in Chrome: 2017-03-21
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ctops@comodo.com
Chrome inclusion status: Included (since M60).

sabre.ct.comodo.com

Base64 Log ID: VYHUwhaQNgFK6gubVzxT8MDkOHhwJQgXL6OqHQcT0ww=
Operator: Comodo
Submitted for inclusion in Chrome: 2017-03-21
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ctops@comodo.com
Chrome inclusion status: Included (since M60).

Special Purpose Logs


ct.googleapis.com/submariner - Log for untrusted roots.

Note that this log is not trusted by Chrome. It only logs certificates that chain to roots that are on track for inclusion in browser roots or were trusted at some previous point. See the announcement blog post.
Base64 Log ID: qJnYeAySkKr0YvMYgMz71SRR6XDQ+/WR73Ww2ZtkVoE=
Operator: Google
Started: 2016-03-22
HTTPS supported:yes
Contact: google-ct-logs@googlegroups.com
Chrome inclusion status: Not included

ct.googleapis.com/daedalus - Log for expired certificates.

Note that this log is not trusted by Chrome. It only logs certificates that have expired. See the announcement post.
Base64 Log ID: HQJLjrFJizRN/YfqPvwJlvdQbyNdHUlwYaR3PEOcJfs=
Operator: Google
Started: 2016-12-19
HTTPS supported:yes
Contact: google-ct-logs@googlegroups.com
Chrome inclusion status: Not included.

ct.googleapis.com/testtube - Test log.

Base64 Log ID: sMyD5aX5fWuvfAnMKEkEhyrH6IsTLGNQt8b9JuFsbHc=
Operator: Google
Started: 2014-08-25
HTTPS supported: yes
Contact: google-ct-logs@googlegroups.com

Note that this log is intended for testing purposes only and will only log certificates that chain to a root explicitly added to it.
To add a test root to Testtube, please email google-ct-logs@googlegroups.com

A test root for Testtube should:
  • Have a certificate "Subject" field that:
    • Includes the word "Test" (to reduce the chances of real certificates being mixed up with test certificates.
    • Identifies the organization that the test root is for (to allow easy classification of test traffic).
  • Not allow real certificates to chain to it, either because:
    • It is a self-signed root CA certificate identified as a test certificate (as above).
    • It is an intermediate CA certificate that chains to a root certificate that is also identified as a test certificate.
  • Be a CA certificate, by:
    • Having CA:TRUE in the Basic Constraints extension.
    • Include the 'Certificate Sign' bit in the Key Usage extension.
Note that for historical reasons Testtube includes some test roots that do not comply with all of the above requirements.

Frozen Logs


ct.googleapis.com/aviator

Base64 Log ID: aPaY+B9kgr46jO65KB1M/HFRXWeT1ETRCmesu09P+8Q=
Operator: Google
Started: 2013-09-30
HTTPS supported: yes
Contact: google-ct-logs@googlegroups.com
Chrome inclusion status: Frozen.

Logs that ceased operation


alpha.ctlogs.org

Base64 Log ID: OTdvVF97Rgf1l0LXaM1dJDe/NHO2U0pINLz3Lmgcg8k=
Operator: Matt Palmer
Submitted for inclusion in Chrome: 2014-08-12
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ops@ctlogs.org
Chrome inclusion status: Not included anymore (was briefly planned for inclusion in M41).

ct.wosign.com

Base64 Log ID: nk/3PcPOIgtpIXyJnkaAdqv414Y21cz8haMadWKLqIs=
Operator: WoSign
Submitted for inclusion in Chrome: 2015-09-22
HTTPS supported: yes
MMD: 24 hours
Contact: ctlog@wosign.com; +86-755-8600 8688
Chrome inclusion status: Applied for inclusion but did not qualify.

log.certly.io

Base64 Log ID: zbUXm3/BwEb+6jETaj+PAC5hgvr4iW/syLL1tatgSQA=
Operator: Certly
Submitted for inclusion in Chrome: 2014-12-14
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: ian@certly.io
Chrome inclusion status: Included (since M43) but disqualified (since M52).

ct.izenpe.com

Base64 Log ID: dGG0oJz7PUHXUVlXWy52SaRFqNJ3CbDMVkpkgrfrQaM=
Operator: Izenpe
Submitted for inclusion in Chrome: 2014-11-10
HTTPS supported: yes
Maximum Merge Delay: 24 hours
Contact: atecnica@izenpe.net
Chrome inclusion status: Included (since M44) but disqualified (since M53).

www.certificatetransparency.cn/ct

Base64 Log ID: 4BJ2KekEllZOPQFHmESYqkj4rbFmAOt5AqHvmQmQYnM=
Operator: Beijing PuChuangSiDa Technology Ltd.
Submitted for inclusion in Chrome: 2016-11-22
HTTPS supported: yes
MMD: 24 hours
Contact: certificatetransparency@outlook.com; +86 (17) 316230-527
Chrome inclusion status: Included (since M58) but disqualified (since M60).

To have another log included in this list, please email the certificate-transparency list.
Comments