"The Mathematics of Cryptography: How to Create and Decrypt Codes" Shin Ichimatsu Price: ¥900 (excluding tax) #ShinIchimatsu #Shin_Ichimatsu #Book #Nature/Mathematics This item has been stored at home for a long time. It was kept in my parents' bookshelf with a bookstore cover. There are some stains and sun-fading on the second photo and the top of the book, but the inside seems to be clean. There are no pets or smokers. Thank you for your understanding.