How was the faulty ShadowCash implementation of ring signatures repaired in February 2016?

Question

The cryptocurrency ShadowCash uses traceable ring signature to anonymize the sender of a transaction. However, these were originally implemented incorrectly, resulting in a partial de-anonymization of ShadowCash from their first implementation until February 2016 by Monero Research Labs researcher, Shen Noether. ^wiki

From the technical perspective, how was Shadowcash's implementation of ring signatures fixed which prevented the partial de-anonymization of it? What was the fix and by whom was it performed?

Answer 1

This is incorrect.

The original implementation of ring signatures is not thought to be faulty.

The original implementation of ring signatures is not from Shadowcash, but from Bytecoin. Shadowcash implemented their own version of it, buggily.

So Shen did not fix ring signatures, though he did find the fault in Shadowcash's reimplementation. I believe Shadowcash eventually fixed their bug after claiming this was FUD.

See https://shnoe.wordpress.com/2016/02/11/de-anonymizing-shadowcash-and-oz-coin/ for the details, and https://github.com/ShenNoether/Deanon for the deanonymization code.