Key generation device, key generation method, and computer program product

A key generation method comprising:

• calculating a key length;
• determining a block size corresponding to a unit of processing in key generation and an outputtable size indicating the size of a key outputtable by the key generation;
• and
• generating a key having the key length by a hash operation using a matrix having a size determined by the block size and the outputtable size.

A computer program product having a non-transitory computer readable medium including programmed instructions, the instructions, when executed by a computer, causing the computer to function as:

• a calculating unit configured to calculate a key length;
• a determining unit configured to determine a block size corresponding to a unit of processing in key generation and an outputtable size indicating the size of a key outputtable by the key generation;
• and
• a generating unit configured to generate a key having the key length by a hash operation using a matrix having a size determined by the block size and the outputtable size.