[3] Leiberich started his career during World War II, conscripted as a soldier and working as a cryptanalyst in Chi IV of the OKW/Chi.

During the Cold War Leiberich and his team worked intensively on the cryptanalysis of double transposition ciphers.

[7] In 1999, Leiberich wrote a report on the history of cryptography in Germany, which appeared in Spektrum der Wissenschaft,[8] the German edition of the Scientific American.

Leiberich's recommendation for the challenge included: These properties were based on Leiberich's own experience, designed with parameters to ensure its own security[7] In 2007, the challenge was published by Klaus Schmeh,[7] in various media channels including his own books, websites and academic and white papers.

[7] In November 2013, George Lasry, Nils Kopal and Arno Wacker solved the double transposition cipher using a ciphertext only hill climbing attack.