The first reason of the Great Cipher used was remained unbroken for 200 years is that the creative idea of replacing syllabus by different numbers. With the development of the cryptography, more and more encrypting methods are invented. This limits the thoughts of people to use previous methods to solve this new encrypted method. Also, it limits people that different alphabets are related to different numbers. It is hard for someone to come up with the idea that the numbers are representing the syllabuses of words. The second reason is that the amount of work is huge and difficult to analyze. With 587 different numbers, trying only one method without making any mistakes during the process itself is difficult to finish. For Bazeries, it takes him three years to finish decrypting the message and he is brave to try the idea of using numbers to represent the syllabus. An attempt to decrypt the method is already time-consuming and boring. Someone may have come up with the same idea with Bazeries, but the difficulty of finishing it held him back. He may mentally tell himself that this idea is impossible since no one has used that before. This thought provides him comfort for not trying the method at all. What’s more, the amount of the work requires people to be patient. Once, people get angry or bored about the decryption; he is more likely to make more mistakes. All these reasons makes the information as a secret for 200 years.