The present invention provides a computer system comprising a system memory, a processor, a cryptoprogram, an I/O port, and an electronic key. The electronic key can be inserted into and removed from the I/O port and contains a programmable memory that stores passwords. The cryptoprogram is used to encrypt and decrypt programs or files stored in the system memory. Encryption of programs or files is accomplished according to a password that is stored in the programmable memory of the electronic key. During decryption, the cryptoprogram searches for the corresponding password in the programmable memory of the key and decrypts the program or file if the password is found.