Patent ID: 7191344

Claim:
A method ( 200 ) for allowing access to a storage device comprising: (a) accepting ( 204 ) a token device ( 20 ) that was plugged into a data port ( 18 ) of a computer ( 10 ) before booting up; (b) after booting up, transmitting ( 206 ) a puzzle (Sn) read from a hard disk storage device ( 12 ) on said computer ( 10 ) to the token device ( 20 ); (c) recognizing ( 208 ) puzzle (Sn) as a challenge, and using an encryption/decryption program to output a dynamic key (Kn) with a token processor ( 22 ) from said puzzle (Sn) in the token device ( 20 ); (d) transmitting ( 210 ) the dynamic key (Kn) through the data port ( 18 ) to a processor ( 14 ) of the computer system; (e) transmitting ( 212 ) an encrypted file key (EFKn) stored on the hard disk storage device ( 12 ) to the processor ( 14 ); (f) decrypting ( 214 ) the encrypted file key (EFKn) with the processor ( 14 ) using the dynamic key (Kn) to generate a clear file key (CFK); (g) storing ( 216 ) the clear file key (CFK) in memory ( 16 ) of the computer ( 10 ) until it is powered down; thereafter, using an encryption/decryption program running on the computer processor ( 14 ), and the clear file key (CFK) in memory ( 16 ), to routinely decrypt data as it is read from hard disk storage device ( 12 ) to computer memory ( 16 ), and to routinely encrypt data as it is written from computer memory ( 16 ) to the hard disk storage device ( 12 ); (h) for a next boot up of computer ( 10 ), automatically generating ( 218 ) a subsequent puzzle (Sn+1); (i) storing the subsequent puzzle (Sn+1) both on the hard disk storage device ( 12 ) and in the token device ( 20 ) so as to overwrite the previous puzzle (Sn); (j) generating ( 222 ) from the subsequent puzzle (Sn+1), a subsequent dynamic key (Kn+1) in the token device ( 20 ); (k) transmitting ( 224 ) the clear file key (CFK) and the subsequent dynamic key (Kn+ 1 ) to the processor ( 14 ) of the computer system; (l) encrypting ( 226 ) the clear file key (CFK) with the subsequent dynamic key to generate a subsequent encrypted file key (EKFn+1); and (m) storing ( 228 ) the subsequent encrypted file key (EKFn+1) on the hard disk storage device ( 12 ).