# Transport Layer Security Transport Layer Security is the protocol family used to authenticate endpoints and protect data in transit for many Internet services. ## Notebook evidence [[Scanned_20260730-1958]], PDF page 41, includes a TLS-labeled school or project mailbox inside the wider domain and organizational-identity ledger. ## Archive significance The acronym may name both the protocol and a project label in this notebook. Those meanings remain distinct: protocol context does not resolve ownership or purpose of [[TLS School]].