Abstract: A protection key for hardware includes a first storage area configured to store a key data used for permission to use software installed in a information processor, a second storage area configured to store a data table including a plurality of random numbers, a receiver configured to receive a cryptography key from the information processor, a coder/decoder configured to encrypt the key data based on the cryptography key by picking one random number from the data table, and a transmitter configured to transmit the encrypted key data to the information processor.

Abstract: An encryption key device can be freely attached to and detached from an information processor encrypting or decrypting data and includes a memory, a pseudorandom number generator, and a controller. The memory stores an application program to operate the encryption key device and a group ID specifying permission for use of the encryption key device. The pseudorandom number generator generates a pseudorandom number according to an encryption function using the group ID stored in the memory as an initial value of the encryption function. The controller causes the pseudorandom number generator to generate the pseudorandom number according to data size received from the information processor operating according to the application program and sends the generated pseudorandom number and the group ID read from the memory to the information processor.

Abstract: A protection key for hardware includes a first storage area configured to store a key data used for permission to use software installed in a information processor, a second storage area configured to store a data table including a plurality of random numbers, a receiver configured to receive a cryptography key from the information processor, a coder/decoder configured to encrypt the key data based on the cryptography key by picking one random number from the data table, and a transmitter configured to transmit the encrypted key data to the information processor.

Abstract: A protection key provided with an information processor includes a memory unit including a first storage area to store first data used for permission to use of software installed in the information processor and a second storage area to store second data, the second data being the same as the data stored in another protection key for permission to use other software installed in the information processor, and a controller configured to determine whether the second data is valid, wherein the controller transmits the second data to the information processor when the second data is valid and transmits the first data to the information processor when the second data is invalid.