Lmao, even the shitcoin Darkcoin cant be compared to the even shittier shitcoin Shadowcash
Shadowcash's implementation of "ring sigs" is mediocre at best. In simple terms, it's kind of like a rusty, broken down version of cryptonote's ring signatures.
Ring sigs are only one part of the Shadow system. They serve as an added layer of obfuscation and are just one piece of the puzzle. The other pieces of the puzzle are dual-key stealth addresses, and non-interactive zero knowledge proofs. If you don't know what those are you should look into them, its cutting edge tech. Its a unique system, and its better than cryptonote imho. Please study this slide show and captions for a complete understanding of how the Shadow System works:
http://www.slideshare.net/shadowcash/presentation3-43827434Also here is a good article to better understand how the system works:
http://www.deepdotweb.com/2015/01/28/shadowcash-zero-knowledge-anonymity/