Businesses dragging their heels over rolling out TLS 1.2 on their website might have an excuse to delay a little longer: Version 1.3 of the TLS (Transport Layer Security) encryption protocol will be finalized later this year, and early deployments of it are already under way.
TLS, the successor to SSL, is used to negotiate secure connections to web or mail servers, encrypting data on the move.
Six years in the making, TLS 1.2 added new, stronger encryption options — but retained all the older, weaker encryption schemes that had gone before in the name of backward compatibility. Unfortunately, this meant that someone able to perform a man-in-the-middle attack could often downgrade connections to a weaker encryption system without the user being aware.
Source: NW Security 1