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Opportunistic encryption involves using a key that might be known, and backing off to non-keyed when the key is not known. It has been mistakenly claimed similar to BTNS (Better Than Nothing Security), which is part of the Anonsec (Anonymous Security) framework by Joe Touch of USC/ISI. BTNS uses unsigned Diffie-Hellman exchanges to establish session keys between parties that have no shared keys or key framework. BTNS does not 'back-off'; in contrast to OE, BTNS allows a unsigned key pair to later be signed using in-band exchanges at other protocol layers, using a combination of Channel Binding and Connection Latching. OE has no relation to BTNS. —Preceding unsigned comment added by Jtouch (talk • contribs) 06:01, 19 January 2010 (UTC)
To the contrary, BTNS is a type of Opportunistic Encryption. Just because it has an additional capability of validating keys does not make the base mode not opportunistic. BTNS's base capability pretty much is the definition of OE, as it encrypts when the receiver is able. — Preceding unsigned comment added by 220.127.116.11 (talk) 00:57, 2 August 2012 (UTC)