Probabilistic Methods for a Japanese Syllable Cipher

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5459)


This paper attacks a Japanese syllable-substitution cipher. We use a probabilistic, noisy-channel framework, exploiting various Japanese language models to drive the decipherment. We describe several innovations, including a new objective function for searching for the highest-scoring decipherment. We include empirical studies of the relevant phenomena, and we give improved decipherment accuracy rates.


Substitution cipher decipherment language modeling 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  1. 1.Information Sciences Institute, Computer Science DepartmentUniversity of Southern CaliforniaMarina del ReyUSA

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