Patent ID: 7167984

Claim:
An approximate message authentication code generated by a cryptography device and comprising a probabilistic checksum generated using as input a message and a shared key and which provides absolute authentication for an origin of the message and approximate integrity for the content of the message, the code being generated according to the following steps: a. receiving a message containing data and arranging the data into a table having |A| columns and T 2 rows, where A and T are integers and T is selected to be an odd integer; b. permuting at least some of the arranged data; c. masking the permuted data; d. copying the permuted and masked data into T S-arrays, each S-array having |A| columns, and determining a majority bit value of each of the |A| columns for each of the T S-arrays; e. using the determined majority bits to create a T-array having |A| columns and T rows and f. determining the majority bit value of reach of the |A| columns in the T array.