Proof, compliance and data
TLS encryption
Acronym: TLS
TLS is the protocol that encrypts exchanges between a browser and a website; it is what protects https addresses and the padlock icon.
It guarantees three things: the confidentiality of the data exchanged, its integrity, and the server's authenticity through its certificate. It succeeded SSL, whose name is still often used out of habit. It protects the path between two points, not the data once it arrives: what the server does with it depends on other measures.
Why it matters for fax
On an online fax service, TLS protects the upload of the document to the server. The rest of the journey, over the phone network to the fax machine, is generally not encrypted: worth knowing before faxing sensitive information.