A computer readable transportable information recording medium includes a recordable area and a read only area. The recordable area allows recording of data thereinto and reading of the data therefrom. The read only area stores a copy judging program, an encrypting program, a recording program, a decoding program, a first password control program, and a second password control program. The copy judging program judges whether a transportable information recording medium has been undergone a copy operation. The encrypting program encrypts data designated and stored in a computer. The recording program records the data encrypted by the encrypting program into the recordable area. The decoding program decodes the data encrypted and stored in the recordable area. The first password control program sets or judges a password when the encrypting program is activated. The second password control program judges a password when the decoding program is activated.