	US 7,519,830 B2
	Secure storage of data
Thomas J. Mihm, Jr., Crystal Lake, Ill. (US); and Eric R. Uner, Carpentersville, Ill. (US)
Assigned to Motorola, Inc., Schaumburg, Ill. (US)
Filed on Aug. 03, 2006, as Appl. No. 11/462,155.
Prior Publication US 2008/0046737 A1, Feb. 21, 2008
Int. Cl. G06F 12/14 (2006.01); G06F 7/04 (2006.01)

U.S. Cl. 713—187 [713/193; 726/26; 726/30]

19 Claims

1. A method for detecting alteration of a first data value encrypted and stored in a memory, the method comprising:

reading an encrypted data address from the memory, the data address being selected at random when the first data value was encrypted and stored in the memory;

decrypting the encrypted data address;

reading a second data value currently stored at the data address in the memory;

reading an encrypted split value from the memory, the split value being a combination of a hash value of the first data value and a third data value that was stored at the data address in the memory when the first data value was encrypted and stored in the memory;

decrypting the encrypted split value;

combining the split value and the second data value to produce a recovered hash value;

calculating a hash value of the first data value;

comparing the recovered hash value to the calculated hash value of the first data value; and

determining the first data value to be altered if the recovered hash value is not equal to the calculated hash value.