Attack on Brands blind signature

eprint.iacr.org/2005/186 is an attack by Xuesheng Zhong on several blind signature schemes, including one widely discussed on the Cypherpunks mailing list back in the 1990s by Stefan Brands. The paper seems to show that it is possible for the bank/mint to recognize blind signatures (i.e. untraceable electronic cash tokens) when they are re-submitted for deposit, which is exactly what the blind signature is supposed to prevent. The math looks right although I haven't tried to look back at Brands' old work to see if it is correctly described in the new paper. CP