According to the Monero's paper on Ring Confidential Transactions, the Ring CT protocol is a currency which:
- requires no trusted setup,
- hides the identity of the recipient of a transaction,
- hides the identity of the originator of a transaction,
- hides the amount in a given transaction.
Although, it seems that an outsider validator is not able to detect the transactor, but is able to detect the group of parties, such that at least one of them has generated the transaction. So, if it's true, the identification of the transactor is not totally protected.
However, since it does not need a trusted set up (unlike zk-SNARKs and similar to zk-STARKs), can "Ring Confidential Transactions" be an alternative to "Zero-Knowledge Proofs" ?