An information processing apparatus includes a TPM, a key management module for managing a key database, a memory, and a file processing module for encrypting and decrypting a file. The TPM stores a first TPM key therein and encrypts a third TPM key. The key management module stores and manages the third TPM key in the database. When the information processing apparatus starts communicating with the tamper-proof device, the key management module receives, from the TPM, a parameter for generating a second TPM key, provides the received parameter to the tamper-proof device, receives from the tamper-proof device the second TPM key which has been encrypted using the first TPM key, and provides the TPM with the second TPM key and with the third TPM key which has been encrypted using the second TPM key. When the second TPM key contains password check information, the TPM receives from the tamper-proof device a password associated with the password check information, and verifies the received password using the password check information. When it is verified that the password is correct, the TPM decrypts the second TPM key using the first TPM key, decrypts the third TPM key using the decrypted second TPM key, and decrypts, using the decrypted third TPM key, an encrypted encryption key for decrypting the file. The file processing module decrypts the file using the decrypted encryption key.