AOS Ring Signatures: The Builder of Transaction Privacy

Well, it’s a New Year (2024), and my New Year’s resolution is to get more in-depth with methods and try and analyse and implement privacy in a mathematical way. And, so, for the 15 years of advancement of blockchain methods, I want to understand the theoretical underpinning of transactional privacy.

One of the best implementations of this is with the Monero cryptocurrency, and which anoymises the sender and the receiver, along with the transaction amount. But, to understand the method that Monero uses, we need to go back to the original ring method produced by Abe, Okhubo and Suzki (AOS), and which produced an elegant solution for elliptic curve methods:

Up to this time, ring signatures used the RSA method, and was rather cumbersome. With AOS, we now had an elliptic curve method:

AOS ring signatures

AOS ring signatures are used in confidential transactions, and where we can hide the signer of a transaction. The method has been…