SSL and TLS are not monolithic encryption entities that you use or do not use to securely connect to email servers, websites, and other systems. SSL and TLS are evolving protocols with many nuances to how they may be configured. The “version” of the protocol and the ciphers used directly impact the level of security achievable through your connections.
Some people use the terms SSL and TLS interchangeably, but TLS (version 1.0 and beyond) is the successor of SSL (version 3.0). See SSL versus TLS – what is the difference? In 2014 we saw that SSL v3 was very weak and should not be used going forward by anyone; TLS v1.0 or higher must be used.
Among the many configuration nuances of TLS, the protocol versions supported (e.g., 1.0, 1.1, 1.2, and 1.3) and which “ciphers” are permitted significantly impact security. A “cipher” specifies the encryption algorithm, the secure hashing (message fingerprinting / authentication) algorithm to be used, and other related things such as how encryption keys are negotiated. Some ciphers that have long been used, such as RC4, have weakened over time and should never be used in secure environments. Other ciphers protect against people who record a secure conversation from being able to decrypt it in the future if somehow the server’s private keys are compromised (perfect forward secrecy).
Given the many choices of ciphers and TLS protocol versions, people are often at a loss as to what is specifically needed for HIPAA compliance. Simply “turning on TLS” without configuring it appropriately is likely to leave your transmission encryption non-compliant.
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SSL and TLS
