Patent ID: 7706532

Claim:
An encryption apparatus, comprising: hold means for holding a part or all input data with a trigger signal and resetting held data with a reset signal; one or a plurality of counters that count up or count down count values with the trigger signal and reset the count values to predetermined values with the reset signal; encryption means for reading the data held by the hold means and one or a plurality of the count values and for encrypting the data held by the hold means and one or a plurality of the count values of the one or plurality of counters; calculation means for calculating the output of the encryption means and input data that are input from the outside according to a first predetermined rule, encrypting the input data, and outputting the encrypted data; a path that inputs a part or all the encrypted data that are output from the calculation means to the hold means; and signal generation means for generating the trigger signal and the reset signal supplied to the hold means and the one or plurality of counters according to a second predetermined rule and/or at predetermined timing, wherein the encryption means reads in parallel the data held by the hold means, one or a plurality of the count values, and a key outputted by the signal generation means, and wherein the input data is sequentially inputted to the calculation means in a predetermined unit, and the data held by the hold means is reset in each predetermined unit so that data in a preceding unit of the input data is excluded from affecting encryption of a current unit of the input data.