Monero is an open-source, privacy-oriented cryptocurrency that launched in 2014. Monero uses cryptography to shield transactions details on their blockchain, the sending and receiving addresses as well as the transaction amounts are obfuscated. Essentially allowing users to send and receive untraceable transactions anonymously.
Monero is in this sense unique as most other blockchains are transparent in nature, all transactions are openly verifiable and traceable.
Monero uses the concepts of ring signatures and stealth addresses to address privacy concerns.
In cryptography, a ring signature is a digital signature that can be performed by any member of a group of users that each have keys. Ring signatures don’t reveal which member of the group signed the transaction. It should be computationally impossible to determine which of the group members’ keys was used to produce the signature.
Stealth addresses are randomly generated addresses for one-time use and are created for every transaction on behalf of the recipient. Stealth addresses obfuscate the actual destination address of a transaction, thus concealing the identity of the receiving user.