# Is K4 solved, known but withheld, or open? · Kryptos > Four answers have been proposed. K4 is solved; its plaintext has been recovered and confirmed by its author. leads, with evidence 1 for, 2 against… Source: https://mysteriesdept.com/mysteries/kryptos/questions/QST0D7HT7T41TBW/is-k4-solved-known-but-withheld-or-open Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) Updated: 2026-10-26T11:57:50+00:00 --- **0** # Is K4 solved, known but withheld, or open? Asked 26 Oct 2026 by [**apollo** ](https://mysteriesdept.com/u/apollo)·4 answers·0·0 following **Answered: K4 is solved; its plaintext has been recovered and confirmed by its author.** Passed its tests and review. ## Where it stands Four answers have been proposed. K4 is solved; its plaintext has been recovered and confirmed by its author. leads, with evidence 1 for, 2 against: partly supported by its tests. Three are still possible. Of the one narrower question under it, none is answered yet. ## Why it matters Since September 2025 the plaintext of K4 has been in the hands of people other than Sanborn, and since November 2025 his method has belonged to a buyer. Which of the three descriptions is right decides what the site should say and what work is still worth doing⁠[[1]](https://mysteriesdept.com/sources/SRC0D7HSY9E4E6S/a-c-i-a-secret-kept-for-35-years-is-found-in-the)⁠[[2]](https://mysteriesdept.com/sources/SRC0D7HSZ0W1S9N/jim-sanborns-complete-kryptos-archive-sells-for-962-500-at)⁠[[3]](https://mysteriesdept.com/sources/SRC0D7HT0041JD9/project-kryptos). ## Answers 4 [**K4 is solved; its plaintext has been recovered and confirmed by its author.** ](https://mysteriesdept.com/mysteries/kryptos/answers/ANS0D7HT8SC1PJH/k4-is-solved-its-plaintext-has-been-recovered-and-confirmed) Partly supported by its tests Evidence: 1 for, 2 against Most likely [**K4 remains unsolved as a cryptographic problem; no one has derived its plaintext and method from the…** ](https://mysteriesdept.com/mysteries/kryptos/answers/ANS0D7HTAZP1F8X/k4-remains-unsolved-as-a-cryptographic-problem-no-one-has) Partly supported by its tests Evidence: 2 for Most likely [**K4's plaintext and method are known to a few holders and deliberately unpublished.** ](https://mysteriesdept.com/mysteries/kryptos/answers/ANS0D7HT9RM4MAQ/k4s-plaintext-and-method-are-known-to-a-few-holders-and) Supported by its tests Evidence: 4 for Most likely [**None of these.** ](https://mysteriesdept.com/mysteries/kryptos/answers/ANS0D7HTBQ448KR/none-of-these) Failed a test; not refuted outright Evidence: none yet Disputed ## History 1. 2021[Bean: no peer-reviewed or verified decryption of K4 exists; published work is diagnostic.](https://mysteriesdept.com/sources/SRC0D7HSXST3N01/cryptodiagnosis-of-kryptos-k4)For: K4 remains unsolved as a cryptographic problem; no one has derived its plaintext and method from the… 1. 2025[Schwartz puts forward: k4 is solved; its plaintext has been recovered and confirmed by its author.](https://mysteriesdept.com/sources/SRC0D7HSY9E4E6S/a-c-i-a-secret-kept-for-35-years-is-found-in-the) 1. 2025[RR Auction puts forward: k4 remains unsolved as a cryptographic problem; no one has derived its plaintext and method from the…](https://mysteriesdept.com/sources/SRC0D7HSYS276ZP/kryptos-k4-discovered-not-solved-heres-what-actually) 1. 2025[Agence France-Presse: sanborn says the find gave the plaintext but not the coding method or the key, which he calls a very…](https://mysteriesdept.com/sources/SRC0D7HSZ8P69KE/auction-of-famed-cia-cipher-shaken-after-archive-reveals)Against: K4 is solved; its plaintext has been recovered and confirmed by its author. 1. 2025[Escoria & Maren: kobek himself says the find is not a cryptographic solve.](https://mysteriesdept.com/sources/SRC0D7HSYH84Z3Y/interview-kryptos-k4-uncovered-jarett-kobek-and-richard)Against: K4 is solved; its plaintext has been recovered and confirmed by its author. 1. 2025[Schwartz: kobek and Byrne assembled a plaintext from archive scraps that matched the released clues in length and…](https://mysteriesdept.com/sources/SRC0D7HSY9E4E6S/a-c-i-a-secret-kept-for-35-years-is-found-in-the)For: K4 is solved; its plaintext has been recovered and confirmed by its author. 1. 2025[RR Auction: the archive sold on 20 November 2025 included Sanborn's handwritten K4 plaintext and the original K4 coding…](https://mysteriesdept.com/sources/SRC0D7HSZ0W1S9N/jim-sanborns-complete-kryptos-archive-sells-for-962-500-at)For: K4's plaintext and method are known to a few holders and deliberately unpublished. 1. 2025[Agence France-Presse: kobek and Byrne refused NDAs but say they will not publish, after letters from the auction house's lawyers.](https://mysteriesdept.com/sources/SRC0D7HSZ8P69KE/auction-of-famed-cia-cipher-shaken-after-archive-reveals)For: K4's plaintext and method are known to a few holders and deliberately unpublished. 1. 2025[Basilio: the Smithsonian sealed the relevant files for fifty years at Sanborn's request.](https://mysteriesdept.com/sources/SRC0D7HSZGG4WDT/after-35-years-a-solution-to-the-cias-kryptos-puzzle-has)For: K4's plaintext and method are known to a few holders and deliberately unpublished. 1. 2025[Vergano: sanborn's position after the find is that K4 has not been solved and that it points toward K5.](https://mysteriesdept.com/sources/SRC0D7HSZRA00RT/artist-releases-final-clues-to-solve-cia-kryptos-puzzle)For: K4 remains unsolved as a cryptographic problem; no one has derived its plaintext and method from the… 1. 2026[Robinson & Huang puts forward: k4's plaintext and method are known to a few holders and deliberately unpublished.](https://mysteriesdept.com/sources/SRC0D7HT0041JD9/project-kryptos) 1. 2026[Robinson & Huang: paradigm says Sanborn entered the plaintext into a verifier and that the firm has not seen it; it has not…](https://mysteriesdept.com/sources/SRC0D7HT0041JD9/project-kryptos)For: K4's plaintext and method are known to a few holders and deliberately unpublished. 1. 26 Oct 2026Asked on this site ## Discussion 0 [Add to the discussion](https://mysteriesdept.com/signin?next=/mysteries/kryptos/questions/QST0D7HT7T41TBW/is-k4-solved-known-but-withheld-or-open%23discussion) Help with this question [ **Propose an answer** Something the evidence could support or rule out ] [ **Propose an answer** Something the evidence could support or rule out ](https://mysteriesdept.com/signin?next=/mysteries/kryptos/questions/QST0D7HT7T41TBW/is-k4-solved-known-but-withheld-or-open%23add-answer) [ **Add evidence** A result for or against an answer ] [ **Add evidence** A result for or against an answer ](https://mysteriesdept.com/signin?next=/mysteries/kryptos/questions/QST0D7HT7T41TBW/is-k4-solved-known-but-withheld-or-open%23add-evidence) [ **Ask a sub-question** A smaller question that would help settle this one ] [ **Ask a sub-question** A smaller question that would help settle this one ](https://mysteriesdept.com/signin?next=/mysteries/kryptos/questions/QST0D7HT7T41TBW/is-k4-solved-known-but-withheld-or-open%23add-question) [ **Add a source** A paper, archive record or image ] [ **Add a source** A paper, archive record or image ](https://mysteriesdept.com/signin?next=/mysteries/kryptos/questions/QST0D7HT7T41TBW/is-k4-solved-known-but-withheld-or-open%23add-source) Where it fits Kryptos **Is K4 solved, known but withheld, or open?** Key question · you're here [What is K5 and will it be released?](https://mysteriesdept.com/mysteries/kryptos/questions/QST0D7HT8HJ3Z98/what-is-k5-and-will-it-be-released)Open · 3 answers, inconclusive [ Ask a question under this one ]