How to Interpret Leakage Analysis Results

[leo6121]

Hello,

I performed a leakage analysis to check whether the hardened binary produced by applying CipherFix to a piece of code I wrote myself is secure against ciphertext side-channel attacks. The result in eval-result.txt was like below.

Can not find equivalent instr memtrace line for #56346/123811/56346 image 4 offset 87f0b (last instr: image 4 offset 88074) 
--> Files don't match
    5950666 bytes missing from instr memtrace
Block 7ffc7058c330
  Unique: 7
Block 7ffc7058c300
  Unique: 4
Block 7ffc7058c310
  Unique: 6
Block 7ffc7058c320
  Unique: 6
Block 7ffc7058c340
  Unique: 6
....
Total 426 blocks
Processed 56346 lines

How should I interpret this result?

[paetscan]

Hi,

thanks for your report! This result is not yet a complete leakage analysis. The important part is that the trace comparison desynchronized quite early and aborted with the given error message. Likely, this instrumented trace needs some manual tweaking first so that the tool can recognize the correct matching sequence.
The comparison tool tries to match every trace entry from the original program with an entry from the instrumented program. If for some reason an evaluation marker is missing or an unexpected case occurs, this matching may not work. Unfortunately, the only remedy here is manual investigation.