On October 25, 2026, a post titled “xkcdRelevanceAgain” appeared in r/ProgrammerHumor. It edited an xkcd comic about generations adopting “funny numbers” so that tech workers nominate the number 4. The punchline is painfully specific: one of the private values used by a trusted certificate authority really was 4.
Two xkcd strips and one very real incident
The edited artwork comes from xkcd #3184, “Funny Numbers,” released in December 2025. In the original, mathematicians add the youth catchphrase “6 7” to a board alongside older number jokes. The October Reddit poster explicitly acknowledged modifying the original. It is a fan edit, not a newly released official strip.
The trigger was the eMudhra certificate incident. On October 17, 2026, a researcher reported that private keys corresponding to eight intermediate certificate authorities were generated with inadequate randomness. Independent technical verification identifies the secret scalar of one P-384 elliptic-curve key as exactly 4. This was a key-generation failure, not evidence that an employee deliberately chose a four-character password or that attackers stole the key from a server.
Certificate authorities help devices decide whether a website's claimed identity is trustworthy. A recoverable signing key could enable forged certificates on clients that still trust the affected chain. Google and Mozilla say they blocked the affected intermediates on October 17. The stakes are real; the absurdity is that an enormous space of possible secret values produced one of the smallest imaginable answers.
The comment section starts checking the prophecies
A prominent comment points out that 4 was “Literally the number xkcd picked long ago.” It refers to xkcd #221, “Random Number,” from 2007: a function advertised as random simply returns 4. A satirical one-line programming joke suddenly looks like an incident report written nineteen years early.
One commenter writes “As the prophecies have foretold”; another replies “fourtold.” It is the entire joke compressed into a pun: substitute four for the first syllable of foretold. Another asks “no 67 yet,” since the edited 2025 strip has displaced the number that was originally its newest entry. A question about “23” sends readers down the much older “23 skidoo” slang rabbit hole. One post, several generations of people laughing at numbers.
There is a second official callback. xkcd #3314, “Vulnerability,” published October 21, includes an image tooltip joking that anyone using 4 as a certificate key should upgrade to 5. That is a joke, not a security recommendation. Real remediation means blocking compromised certificates and fixing affected trust stores or software.
An original sketch: the number interview
Interviewer: “What makes you qualified?”
Number 4: “I'm memorable.”
Interviewer: “And your weakness?”
Number 4: “Everybody can guess me.”
Interviewer: “Number 5, can you replace this candidate?”
Number 5: “Only if you promise not to call that a security patch.”
The dialogue above is an original editorial gag, not a Reddit quotation.
The takeaway
The humor is not that a number is intrinsically unsafe. It is that a 2007 random-number joke, a 2025 meme about funny numbers, a genuine 2026 security failure, and an October 25 fan edit all converge on the same digit. The smallest part of the story is the key. The longest part is the internet explaining why 4 is suddenly famous.
References (7)
- Reddit r/ProgrammerHumor, “xkcdRelevanceAgain”, 2026-10-25: https://www.reddit.com/r/ProgrammerHumor/comments/1xf48m8/xkcdrelevanceagain/
- xkcd #3184, “Funny Numbers”, 2025-12: https://xkcd.com/3184/
- xkcd #221, “Random Number”, 2007: https://xkcd.com/221/
- xkcd #3314, “Vulnerability”, 2026-10-21: https://xkcd.com/3314/
- Google Chrome Security, eMudhra notice, 2026-10-20: https://blog.google/security/protecting-chrome-and-android-users-from-compromised-emudhra-intermediate-ca-certificates/
- Mozilla Security Team, eMudhra notice, 2026-10-20: https://blog.mozilla.org/security/2026/10/20/protecting-firefox-users-following-the-compromise-of-emudhra-intermediate-certificates/
- Independent technical verification, 2026-10-21: https://d4.key64.com/
