Ring CT

The Ring CT (Confidential Transactions) is how the transaction amounts are concealed in Monero (XMR). These can include the cryptographic proof that the sum of the input amounts is as same as the output amount, without revealing the numbers themselves. This means that one can track which address sent and received cryptocurrency. It was first implemented in the block block #1220516 in January 2017, and then in September in the same year. The feature finally became mandatory throughout all of the transactions that were conducted on the network itself.