Atomic swaps are a smart-contract technology that enable the exchange of one cryptocurrency for another without using intermediaries such as 3rd party exchanges. Atomic swaps occur as smart-contract events within the respective blockchains in a cryptographically secure manner. Atomic swaps are cornerstone of DEX capability.
Sphere 10 designed and implemented atomic swap capability into Pascal version 5 via the in-protocol account exchanging mechanism. An Account can be time-locked and hash-locked to a counterparty granting that counterparty the option to take ownership of that account (or the coins within) by simply unlocking the hash-lock within the time-lock period.