correlation power analysis

Recover the key

A chip is encrypting with a secret key. Every time it computes SBOX[plaintext ^ key] it burns slightly more power for every set bit, and that leaks. Steal the key before the session closes.

1. 01captureTraces are limited. Each one makes the correlation a little sharper.
2. 02read the chartOne of the 256 candidates is the real key byte. It rises out of the noise as traces accumulate; the tallest bar is your answer.
3. 03commitClick the bar that stands clear of the rest. Guess wrong and you lose traces and seconds.
4. 04repeat, harderFour bytes, each noisier than the last. Whatever you do not spend carries into the next byte, so a fast first byte funds the fourth.

choose a difficulty

• [ easy ]120 / 180 / 260 / 350 traces per byte60 seconds 
• [ normal ]180 / 350 / 580 / 870 traces per byte90 seconds 
• [ hard ]350 / 790 / 1400 / 1900 traces per byte150 seconds 

score = seconds left × 10 + traces left when the key is out, shown out of 100 for the level. Unspent traces carry into the next byte. A lock is safe once the leading bar is ~0.12 of correlation clear of the rest; earlier is a gamble, later is wasted budget and clock.

The attack is real: a genuine AES S-box, a Hamming-weight leakage model and Pearson correlation across all 256 guesses. Only the device and its noise are simulated. On real hardware this is done with a ChipWhisperer, which is what the hardware security lab covers.