For the past few weeks, I have been working with several colleagues on a new cartoon series for my employer called Evi & Den.

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On September 3, 2026, US researcher Eric Lu announced that he had successfully factored RSA-260, an RSA challenge number consisting of 260 decimal digits or 862 bits. This surpasses the previous factoring record, RSA-250 (829 bits), which dated back to 2020. The achievement marks the largest RSA challenge number ever factored.

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I’m happy to announce that my new book, Post-Quanten-Kryptografie (“Post-Quantum Cryptography”), has just been published.

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Among the many unsolved historical ciphers, one mystery that I find particularly intriguing is the Ohio Cryptogram. More than a century after its publication, this encrypted message remains unsolved.

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On this website, you will find a wide range of information about the history of cryptography, codebreaking, and related topics.

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