otamajakusi / aes-dpa-poc Goto Github PK

This repository is forked from tiny-AES-C and add POC to demonstrate AES Differential Power Analysis(=DPA).

Since last round of AES encryption doesn't have MixColumn, there are direct relationship between output cipher text and AES key.

To be more specific, if we can have a hamming-distance between output cipher text and last block of expand key for a large number of pattern, we can guess actual AES key. AES key can be calculated back from the last block of expand key.

To guess the actual AES key by DPA, the following conditions are required:

• a number of AES operation can be issued to generate for each different output.
• output cipher text can be observed.
• hamming-distance can be observed.

Detecting actual hamming-distance might be difficult but if there is relationship between power consumption and hamming-distance and if we can observe power consumption, we can use it instead of hamming-distance.

This POC is running on the ideal condition which can detect actual hamming-distance directly by modifying AES function, but if we can observe power consumption, same strategy can be adopted.

$ make
$ ./dpa.elf