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hermeznetwork / circuits

Implements hermez network zk-Snarks circuits
GNU Affero General Public License v3.0
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Under-constrained Circuit #55

Open UIZorrot opened 8 months ago

UIZorrot commented 8 months ago

It seemed like this was a legacy repo, however, it may still lurk in the newest version maybe?

https://github.com/hermeznetwork/circuits/blob/master/src/lib/utils-bjj.circom

In L#12 BitsCompressed2AySign, the input signal bjjCompressed is not fully constrained. 

    for (i = 0; i < 254; i++) {
        b2nAy.in[i] <== bjjCompressed[i];
    }

The bjjCompressed[254] seemed not been constrained by the loop and other statements. As a result, this bug maybe used for forged fake proof.