Editing Secure channel (section)

==Modeling a secure channel==
Security definitions for a secure channel try to model its properties independently from its concrete instantiation. A good understanding of these properties is needed before designing a secure channel, and before being able to assess its appropriateness of employment in a cryptographic protocol. This is a topic of [[provable security]]. A definition of a secure channel that remains secure, even when used in arbitrary cryptographic protocols is an important building block for [[Universal composability|universally composable]] cryptography.{{citation needed|date=November 2024}}

A universally composable authenticated channel<!-- What is an Authenticated Channel?  Maybe make a page on it --> can be built using [[digital signatures]] and a [[public key infrastructure]].<ref>Ran Canetti: Universally Composable Signatures, Certification, and Authentication. CSFW 2004, http://eprint.iacr.org/2003/239</ref>

Universally composable confidential channels are known to exist under [[computational hardness assumptions]] based on [[hybrid encryption]] and a [[public key infrastructure]].<ref>Waka Nagao, Yoshifumi Manabe, Tatsuaki Okamoto: A Universally Composable Secure Channel Based on the KEM-DEM Framework. TCC 2005: 426-444</ref>