Method and apparatus for usage protection of data files using split key and unique variable

A method for enabling use of an unencrypted data file protected against unauthorized usage with a split key encryption system, the method comprising the steps of:

• providing an encrypted unique variable, the unencrypted data file, and a key storage device with a random number;
• decrypting the encrypted unique variable to produce a unique variable using the random number from the key storage device;
• comparing the unique variable to a terminal number;
• and
• enabling the use of the unencrypted data file if the unique variable matches the terminal number.

A split key encryption system for crypto-sealing an unencrypted data file comprising:

• unique variable entry means for generating a unique variable;
• random number means coupled to the unique variable entry means, the random number means to generate a random number and to write the random number;
• key storage device means coupled to the random number means, the key storage device means for receiving the random number;
• encryption means coupled to the unique variable entry means and to the random number means, the encryption means for combining the unique variable and the random number to generate an encryption variable;
• and
• storage means coupled to the encryption means, the storage means for storing the encryption variable and the unencrypted data file.

A split key decryption system to unseal an unencrypted data file which has been crypto-sealed, the split key decryption system comprising:

• key storage device means for storing a random number;
• terminal means coupled to the key storage device means;
• terminal input means coupled to the terminal means;
• decryption means for decrypting the encrypted unique variable to produce a unique variable using the random number;
• storage means coupled to the terminal input means, the storage means for storing an encrypted unique variable and the unencrypted data file, and
• comparator means coupled to the decryption means, the comparator means for comparing the unique variable with the terminal number.