4d2.su: 4d2 dot org Security Status (Beta)
==========================================

About this application - click to show
The problem: We've recently seen privacy-oriented services come under attack in several ways, from legislative saber-rattling like the EU's Chat Control initiative to an extremely concerning Man-in-the-Middle TLS attack where major hosting companies likely cooperated with law enforcement to violate the privacy of jabber.ru users.

In the jabber.ru attack, hosting companies used their privileged network position to obtain phony TLS certificates for jabber.ru services. These were then secretly used to create an intermediate termination point for secure traffic. Users and site admins saw that connections were encrypted, but communication was presumably being decrypted and funneled elsewhere. This continued for months before it was noticed.

How we're defending ourselves: We already take industry standard precautions such as publishing restrictive CAA records. On this page we try to close some remaining gaps by testing the validity of our own certificates using as many mutually uncooperative parties as possible. This doesn't do anything to prevent an attack, but it makes it as difficult as possible for a MitM attack against us to go unnoticed. Here's how it works: This is not absolute protection from an impersonation attack, or anything close. It just tries to make such an attack as inconvenient, expensive and obvious as possible.

Install our Proof of Security Client for automated monitoring from a machine you trust.
Service NameLocal FingerprintFingerprint to ClientLocal ExpiryExpiry to ClientLE Account IDTrust?
4d2.link
54:5F:C1:F0:F2:9D:74:7950:85:20:C4:85:28:D6:09:07:39:4B:97:01:9D:B1:E6:E4:6D:50:4E:D6:92:2C:45:54:5F:C1:F0:F2:9D:74:79
54:5F:C1:F0:F2:9D:74:7950:85:20:C4:85:28:D6:09:07:39:4B:97:01:9D:B1:E6:E4:6D:50:4E:D6:92:2C:45:54:5F:C1:F0:F2:9D:74:79
Sep 20 22:02:44 2025Jun 22 22:02:45 2025 - Sep 20 22:02:44 2025
Sep 20 22:02:44 2025Jun 22 22:02:45 2025 - Sep 20 22:02:44 2025
76782206https://acme-v02.api.letsencrypt.org/acme/acct/76782206
OK
4d2.org
B2:C8:80:4C:D1:7A:A3:47E8:2E:68:79:DF:2C:EF:C7:A0:AC:45:2E:FE:C1:FF:A2:22:9D:76:9B:CA:E6:04:6B:B2:C8:80:4C:D1:7A:A3:47
B2:C8:80:4C:D1:7A:A3:47E8:2E:68:79:DF:2C:EF:C7:A0:AC:45:2E:FE:C1:FF:A2:22:9D:76:9B:CA:E6:04:6B:B2:C8:80:4C:D1:7A:A3:47
Sep 20 22:02:53 2025Jun 22 22:02:54 2025 - Sep 20 22:02:53 2025
Sep 20 22:02:53 2025Jun 22 22:02:54 2025 - Sep 20 22:02:53 2025
76782206https://acme-v02.api.letsencrypt.org/acme/acct/76782206
OK
4d2.social
E6:E7:42:55:7B:D1:04:8C5F:7A:2F:93:C5:63:EB:13:EB:52:5D:5B:9F:4D:C9:FF:D9:59:FF:DF:D0:E7:2C:AD:E6:E7:42:55:7B:D1:04:8C
E6:E7:42:55:7B:D1:04:8C5F:7A:2F:93:C5:63:EB:13:EB:52:5D:5B:9F:4D:C9:FF:D9:59:FF:DF:D0:E7:2C:AD:E6:E7:42:55:7B:D1:04:8C
Nov 10 06:08:13 2025Aug 12 06:08:14 2025 - Nov 10 06:08:13 2025
Nov 10 06:08:13 2025Aug 12 06:08:14 2025 - Nov 10 06:08:13 2025
1801268617https://acme-v02.api.letsencrypt.org/acme/acct/1801268617
OK
4d2.su
05:DF:D4:1B:4E:5A:6E:4E42:79:15:CB:D7:A2:23:3C:84:73:B7:63:2F:A4:74:A3:8A:48:96:A3:7D:1F:A9:33:05:DF:D4:1B:4E:5A:6E:4E
Verify this manuallyCheck cert details in your browser - Verify this SHA-256 fingerprint manually
Sep 29 13:01:16 2025Jul 1 13:01:17 2025 - Sep 29 13:01:16 2025
Verify this manuallyCheck cert details in your browser - Verify this manually
2014851357https://acme-v02.api.letsencrypt.org/acme/acct/2014851357
ImplicitThis server can't attest for itself
bayard.4d2.org
B2:C8:80:4C:D1:7A:A3:47E8:2E:68:79:DF:2C:EF:C7:A0:AC:45:2E:FE:C1:FF:A2:22:9D:76:9B:CA:E6:04:6B:B2:C8:80:4C:D1:7A:A3:47
B2:C8:80:4C:D1:7A:A3:47E8:2E:68:79:DF:2C:EF:C7:A0:AC:45:2E:FE:C1:FF:A2:22:9D:76:9B:CA:E6:04:6B:B2:C8:80:4C:D1:7A:A3:47
Sep 20 22:02:53 2025Jun 22 22:02:54 2025 - Sep 20 22:02:53 2025
Sep 20 22:02:53 2025Jun 22 22:02:54 2025 - Sep 20 22:02:53 2025
76782206https://acme-v02.api.letsencrypt.org/acme/acct/76782206
OK
bbs.4d2.org
BF:A0:AF:8A:4C:44:C6:0199:57:B9:AC:00:3F:4E:C6:B2:F0:DA:D3:02:B8:2A:37:15:A3:A5:26:4E:3A:F8:20:BF:A0:AF:8A:4C:44:C6:01
BF:A0:AF:8A:4C:44:C6:0199:57:B9:AC:00:3F:4E:C6:B2:F0:DA:D3:02:B8:2A:37:15:A3:A5:26:4E:3A:F8:20:BF:A0:AF:8A:4C:44:C6:01
Oct 24 03:56:39 2025Jul 26 03:56:40 2025 - Oct 24 03:56:39 2025
Oct 24 03:56:39 2025Jul 26 03:56:40 2025 - Oct 24 03:56:39 2025
2077936547https://acme-v02.api.letsencrypt.org/acme/acct/2077936547
OK
cinny.4d2.org
CC:7C:FF:43:A4:16:A1:708F:A0:90:E6:32:7D:6D:78:7C:43:29:BE:B2:2B:47:FB:B7:4B:CF:C7:7B:94:70:47:CC:7C:FF:43:A4:16:A1:70
CC:7C:FF:43:A4:16:A1:708F:A0:90:E6:32:7D:6D:78:7C:43:29:BE:B2:2B:47:FB:B7:4B:CF:C7:7B:94:70:47:CC:7C:FF:43:A4:16:A1:70
Oct 21 00:14:49 2025Jul 23 00:14:50 2025 - Oct 21 00:14:49 2025
Oct 21 00:14:49 2025Jul 23 00:14:50 2025 - Oct 21 00:14:49 2025
1434949786https://acme-v02.api.letsencrypt.org/acme/acct/1434949786
OK
depot.4d2.org
BC:F9:51:65:A9:2A:6C:300B:35:96:21:69:0A:A3:56:DA:BD:27:F6:C9:28:8C:21:C1:04:B8:1D:9C:32:51:BC:BC:F9:51:65:A9:2A:6C:30
BC:F9:51:65:A9:2A:6C:300B:35:96:21:69:0A:A3:56:DA:BD:27:F6:C9:28:8C:21:C1:04:B8:1D:9C:32:51:BC:BC:F9:51:65:A9:2A:6C:30
Nov 10 06:07:48 2025Aug 12 06:07:49 2025 - Nov 10 06:07:48 2025
Nov 10 06:07:48 2025Aug 12 06:07:49 2025 - Nov 10 06:07:48 2025
1914608496https://acme-v02.api.letsencrypt.org/acme/acct/1914608496
OK
element.4d2.org
4E:B2:9A:18:B4:E0:3B:1DD6:E5:47:44:FB:A6:01:8D:7C:C2:BE:C7:B4:DB:86:BF:6C:35:A3:3B:5B:89:09:59:4E:B2:9A:18:B4:E0:3B:1D
4E:B2:9A:18:B4:E0:3B:1DD6:E5:47:44:FB:A6:01:8D:7C:C2:BE:C7:B4:DB:86:BF:6C:35:A3:3B:5B:89:09:59:4E:B2:9A:18:B4:E0:3B:1D
Oct 21 00:14:33 2025Jul 23 00:14:34 2025 - Oct 21 00:14:33 2025
Oct 21 00:14:33 2025Jul 23 00:14:34 2025 - Oct 21 00:14:33 2025
1434949786https://acme-v02.api.letsencrypt.org/acme/acct/1434949786
OK
jitsi.4d2.org
10:BE:63:8C:E6:C4:59:2F1D:84:01:CD:49:BC:40:A4:EB:9A:49:FB:68:DA:70:B9:FA:7B:4C:BC:4C:5E:F1:2B:10:BE:63:8C:E6:C4:59:2F
10:BE:63:8C:E6:C4:59:2F1D:84:01:CD:49:BC:40:A4:EB:9A:49:FB:68:DA:70:B9:FA:7B:4C:BC:4C:5E:F1:2B:10:BE:63:8C:E6:C4:59:2F
Oct 21 00:14:26 2025Jul 23 00:14:27 2025 - Oct 21 00:14:26 2025
Oct 21 00:14:26 2025Jul 23 00:14:27 2025 - Oct 21 00:14:26 2025
1434949786https://acme-v02.api.letsencrypt.org/acme/acct/1434949786
OK
lemmy.4d2.org
E7:C5:5C:01:6A:B9:36:EA88:A6:69:76:14:E8:49:F0:A6:94:F0:4C:2B:7C:4E:F1:BB:2B:9F:39:EE:44:A8:29:E7:C5:5C:01:6A:B9:36:EA
E7:C5:5C:01:6A:B9:36:EA88:A6:69:76:14:E8:49:F0:A6:94:F0:4C:2B:7C:4E:F1:BB:2B:9F:39:EE:44:A8:29:E7:C5:5C:01:6A:B9:36:EA
Sep 20 22:04:39 2025Jun 22 22:04:40 2025 - Sep 20 22:04:39 2025
Sep 20 22:04:39 2025Jun 22 22:04:40 2025 - Sep 20 22:04:39 2025
2055798447https://acme-v02.api.letsencrypt.org/acme/acct/2055798447
OK
matrix.4d2.org
F4:82:1C:9E:2B:67:8B:6D7C:8F:E9:15:B5:00:D9:66:B6:50:D8:65:C9:CC:09:C0:C6:81:03:FD:03:04:61:05:F4:82:1C:9E:2B:67:8B:6D
F4:82:1C:9E:2B:67:8B:6D7C:8F:E9:15:B5:00:D9:66:B6:50:D8:65:C9:CC:09:C0:C6:81:03:FD:03:04:61:05:F4:82:1C:9E:2B:67:8B:6D
Oct 21 00:14:39 2025Jul 23 00:14:40 2025 - Oct 21 00:14:39 2025
Oct 21 00:14:39 2025Jul 23 00:14:40 2025 - Oct 21 00:14:39 2025
1434949786https://acme-v02.api.letsencrypt.org/acme/acct/1434949786
OK
pad.4d2.org
B9:12:B9:6E:55:49:B9:3251:3E:D8:63:26:14:2C:23:3A:B4:46:46:FB:5E:CE:D4:22:78:B2:E6:61:78:9E:C1:B9:12:B9:6E:55:49:B9:32
B9:12:B9:6E:55:49:B9:3251:3E:D8:63:26:14:2C:23:3A:B4:46:46:FB:5E:CE:D4:22:78:B2:E6:61:78:9E:C1:B9:12:B9:6E:55:49:B9:32
Nov 10 06:08:03 2025Aug 12 06:08:04 2025 - Nov 10 06:08:03 2025
Nov 10 06:08:03 2025Aug 12 06:08:04 2025 - Nov 10 06:08:03 2025
1914608496https://acme-v02.api.letsencrypt.org/acme/acct/1914608496
OK
padsbx.4d2.org
B9:12:B9:6E:55:49:B9:3251:3E:D8:63:26:14:2C:23:3A:B4:46:46:FB:5E:CE:D4:22:78:B2:E6:61:78:9E:C1:B9:12:B9:6E:55:49:B9:32
B9:12:B9:6E:55:49:B9:3251:3E:D8:63:26:14:2C:23:3A:B4:46:46:FB:5E:CE:D4:22:78:B2:E6:61:78:9E:C1:B9:12:B9:6E:55:49:B9:32
Nov 10 06:08:03 2025Aug 12 06:08:04 2025 - Nov 10 06:08:03 2025
Nov 10 06:08:03 2025Aug 12 06:08:04 2025 - Nov 10 06:08:03 2025
1914608496https://acme-v02.api.letsencrypt.org/acme/acct/1914608496
OK
vault.4d2.org
B2:C8:80:4C:D1:7A:A3:47E8:2E:68:79:DF:2C:EF:C7:A0:AC:45:2E:FE:C1:FF:A2:22:9D:76:9B:CA:E6:04:6B:B2:C8:80:4C:D1:7A:A3:47
B2:C8:80:4C:D1:7A:A3:47E8:2E:68:79:DF:2C:EF:C7:A0:AC:45:2E:FE:C1:FF:A2:22:9D:76:9B:CA:E6:04:6B:B2:C8:80:4C:D1:7A:A3:47
Sep 20 22:02:53 2025Jun 22 22:02:54 2025 - Sep 20 22:02:53 2025
Sep 20 22:02:53 2025Jun 22 22:02:54 2025 - Sep 20 22:02:53 2025
76782206https://acme-v02.api.letsencrypt.org/acme/acct/76782206
OK
video.4d2.org
E7:C5:5C:01:6A:B9:36:EA88:A6:69:76:14:E8:49:F0:A6:94:F0:4C:2B:7C:4E:F1:BB:2B:9F:39:EE:44:A8:29:E7:C5:5C:01:6A:B9:36:EA
E7:C5:5C:01:6A:B9:36:EA88:A6:69:76:14:E8:49:F0:A6:94:F0:4C:2B:7C:4E:F1:BB:2B:9F:39:EE:44:A8:29:E7:C5:5C:01:6A:B9:36:EA
Sep 20 22:04:39 2025Jun 22 22:04:40 2025 - Sep 20 22:04:39 2025
Sep 20 22:04:39 2025Jun 22 22:04:40 2025 - Sep 20 22:04:39 2025
2055798447https://acme-v02.api.letsencrypt.org/acme/acct/2055798447
OK
Last updated at Aug 18 09:10:12 2025. All times UTC.
Note that cdn.4d2.org, static.4d2.org and cdn.4d2.social are operated by our CDN vendor Bunny.net. They issue their own certificates.
These fingerprints are not shown here, and the "@" CAA records in the 4d2.org and 4d2.social zones are relaxed to allow this issuance.


Last update from arthur at Aug 18 09:10:01 2025
     Linux arthur.4d2.org 6.13.7-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 13 Mar 2025 18:12:00 +0000 x86_64 GNU/Linux
     UUID Received: c6759b00-fb54-4883-bbfa-5091af39a47b
     UUID Sent: Compare
Last update from bayard at Aug 18 09:10:00 2025
     FreeBSD bayard.4d2.org 14.2-RELEASE-p1 FreeBSD 14.2-RELEASE-p1 GENERIC amd64
     UUID Received: 1e6c51d2-7c13-11f0-81e4-00163ca40e3c
     UUID Sent: Compare
Last update from marvin at Aug 18 09:10:00 2025
     Linux marvin.4d2.org 6.14.6-arch1-1 #1 SMP PREEMPT_DYNAMIC Fri, 09 May 2025 17:36:18 +0000 x86_64 GNU/Linux
     UUID Received: 80d19c6d-116c-4da4-a283-0f0ba2152203
     UUID Sent: Compare

What attacks are still possible, and how do I mitigate them?
How can I find out right away if there's a new security problem?
You can install our Proof of Security Client on a machine you own and schedule it to run regularly.

Back to 4d2 dot org