Encryption key generating apparatus and computer program product

An encryption key generating apparatus comprising:

• a converting unit configured to convert input data with the use of a physically unclonable function and outputs output data;
• a memory to store a pattern data which is obtained by cyclically bit-shifting the output data by an amount of shift indicated by confidential data;
• a generating unit configured to generate an encryption key on the basis of the confidential data;
• and
• a comparing unit configured to, while cyclically bit-shifting the output data, compare the output data with the pattern data so as to detect an amount of cyclic shift at the time when the output data is similar to the pattern data, wherein
• the generating unit reproduces, as the confidential data, the amount of cyclic shift detected by the comparing unit and reproduces the encryption key on the basis of the confidential data that has been reproduced.

A computer program product comprising a computer-readable medium containing a computer program that causes a computer to execute:

• converting input data with the use of a physically unclonable function and outputting output data;
• storing a plurality of pattern data in a memory, each of pattern data being a partial data in the output data indicated by one of a plurality of index data;
• generating an encryption key on the basis of the plurality of index data;
• and
• comparing the output data with the plurality of pattern data so as to detect a plurality of locations in the output data at which partial data similar to the plurality of pattern data is present, wherein
• the generating includes reproducing, as the plurality of index data, the plurality of locations detected at the comparing and reproducing the encryption key on the basis of the plurality of index data that have been reproduced.

A computer program product comprising a computer-readable medium containing a computer program that causes a computer to execute:

• converting input data with the use of a physically unclonable function and outputting output data;
• storing a pattern data in a memory, the pattern data being obtained by cyclically bit-shifting the output data by an amount of shift indicated by confidential data;
• generating an encryption key on the basis of the confidential data;
• and
• comparing, while cyclically bit-shifting the output data, the output data with the pattern data so as to detect an amount of cyclic shift at the time when the output data is similar to the pattern data, wherein
• the generating includes reproducing, as the confidential data, the amount of cyclic shift detected at the comparing and reproducing the encryption key on the basis of the confidential data that has been reproduced.