%0 Journal Article %1 lasry2014dct %A Lasry, George %A Kopal, Nils %A Wacker, Arno %D 2014 %J Cryptologia %K Attack Challenge Ciphers Climbing Columnar Cryptanalysis Dictionary Doppelwürfel Double Hill Manual Transposition Unsolved itegpub kopal lasry myown %P 197-214 %T Solving the Double Transposition Challenge with a Divide and Conquer Approach %U https://www.uni-kassel.de/eecs/fileadmin/datas/fb16/Fachgebiete/UC/papers/Solving_the_Double_Transposition_Challenge_with_a_Divide_and_Conquer_Approach.pdf %V 38 %X The double transposition cipher was considered to be one of the most secure types of manual ciphers. It was extensively used in both World Wars and during the Cold War. In 1999, Otto The double transposition cipher was considered to be one of the most secure types of manual ciphers. It was extensively used in both World Wars and during the Cold War. In 1999, Otto Leiberich, the former head of the German federal office for information security, suggested that a double transposition challenge be published with specific parameters designed to ensure its security. Such a challenge was published by Klaus Schmeh in 2007. In November 2013 we solved the challenge using a ciphertext only hill climbing attack. We also solved the challenge using a dictionary attack. In this paper we describe both methods, which are based on a "divide and conquer" approach. We additionally discuss the impact of our solutions with respect to the general security of the double transposition cipher.

@article{lasry2014dct, abstract = {The double transposition cipher was considered to be one of the most secure types of manual ciphers. It was extensively used in both World Wars and during the Cold War. In 1999, Otto The double transposition cipher was considered to be one of the most secure types of manual ciphers. It was extensively used in both World Wars and during the Cold War. In 1999, Otto Leiberich, the former head of the German federal office for information security, suggested that a double transposition challenge be published with specific parameters designed to ensure its security. Such a challenge was published by Klaus Schmeh in 2007. In November 2013 we solved the challenge using a ciphertext only hill climbing attack. We also solved the challenge using a dictionary attack. In this paper we describe both methods, which are based on a "divide and conquer" approach. We additionally discuss the impact of our solutions with respect to the general security of the double transposition cipher.}, added-at = {2013-12-18T13:52:15.000+0100}, author = {Lasry, George and Kopal, Nils and Wacker, Arno}, biburl = {https://www.bibsonomy.org/bibtex/266c7045fad6222945a0b895950e92e3a/wacker}, description = {http://www.tandfonline.com/doi/full/10.1080/01611194.2014.915269#tabModule}, interhash = {8d2c7fa8755431f0c7487b8ea6834bbd}, intrahash = {66c7045fad6222945a0b895950e92e3a}, journal = {Cryptologia}, keywords = {Attack Challenge Ciphers Climbing Columnar Cryptanalysis Dictionary Doppelwürfel Double Hill Manual Transposition Unsolved itegpub kopal lasry myown}, month = {June}, pages = {197-214}, timestamp = {2016-05-30T12:35:08.000+0200}, title = {Solving the Double Transposition Challenge with a Divide and Conquer Approach}, url = {https://www.uni-kassel.de/eecs/fileadmin/datas/fb16/Fachgebiete/UC/papers/Solving_the_Double_Transposition_Challenge_with_a_Divide_and_Conquer_Approach.pdf}, volume = 38, year = 2014 }