Hash value calculation apparatus and method thereof

A hash value calculation apparatus, which calculates a hash value of a message, comprising:

• an input unit adapted to input an extended block obtained from a message to be processed;
• a plurality of hash value calculation units adapted to execute a hash value calculation of the input block and to output a hash intermediate value, said plurality of hash value calculation units being arranged in correspondence with different hash algorithms;
• a switching unit adapted to switch the hash value calculation unit to be activated, based on a hash algorithm to be used;
• an intermediate value storage unit adapted to store a hash intermediate value output from the active hash value calculation unit in association with a message to be processed;
• and
• an output unit adapted to output a hash intermediate value associated with all blocks of the message to be processed as a hash value of the message.

A hash value calculation method for a hash value calculation apparatus, which calculates a hash value of a message, comprising:

• an input step of inputting an extended block obtained from a message to be processed;
• a hash value calculation step of executing a hash value calculation of the input block and outputting a hash intermediate value;
• a storage step of storing the hash intermediate value output in the hash value calculation step for the message to be processed in one of a plurality of intermediate value storage units;
• an output step of outputting a hash intermediate value associated with all blocks of the message to be processed as a hash value of the message;
• and
• a hash value calculation control step of controlling hash value calculations for a plurality of messages by switching the intermediate value storage units used to store the hash intermediate value output in the hash value calculation step.

A hash value calculation method for a hash value calculation apparatus, which calculates a hash value of a message, comprising:

• an input step of inputting an extended block obtained from a message to be processed;
• a hash value calculation step of executing, in one of a plurality of hash value calculation units arranged in correspondence with different hash algorithms, a hash value calculation of the input block and outputting a hash intermediate value;
• a switching step of switching the hash value calculation unit to be activated based on a hash algorithm to be used;
• an intermediate value storage step of storing, in a storage unit, a hash intermediate value output in the active hash value calculation step in association with a message to be processed;
• and
• an output step of outputting a hash intermediate value associated with all blocks of the message to be processed as a hash value of the message.