The invention relates to the field of 
information security, in particular to an information 
identification system and an information identification method. The information 
identification system comprises transaction platforms, a gateway, a 
payment platform, a secret 
key management platform, a first FPE (
format preserving encryption) encryptor and a second FPE encryptor, wherein each transaction platform is used for acquiring sensitive information and generating and sending a transaction request, the gateway is connected with the transaction platforms and used for providing an 
access port for the transaction platforms, the 
payment platform is connected with the gateway and used for achieving 
payment for the transaction request, the secret 
key management platform is connected with the payment platform and used for managing and assigning secret key information of the transaction platforms, the first FPE encryptor is connected with the gateway and used for achieving identification of the sensitive information in the transaction request, and the second FPE encryptor is connected with the secret 
key management platform and used for decrypting the sensitive information subjected to identification. The information 
identification system centers on the secret key management platform, secret keys are distributed to each transaction platform, and the sensitive information is encrypted by FPE, so that no change on data length during sensitive 
information transmission is guaranteed, and security of the sensitive information is ensured.