An Enhanced User Authentication Protocol Based on Elliptic Curve Cryptosystem in Cloud Computing Environment

Table 2

Notations in BAN logic.

	believes , i.e., the principal believes the statement is true.
	sees , i.e., the principal receives a message that contains .
	has jurisdiction over , i.e., the principal can generates or computes .
	said , i.e., the principal has sent a message containing .
	is fresh, i.e., is sent in a message only at the current run of the protocol, it is usually a timestamp or a random number.
	is the shared key for and .
	is the secret known only to and or some principals trusted by them.
	combined with , and usually is a secret.
	encrypted with .
or	: the message-meaning rule.; This rule will be used in the proving process.
	: the nonce-verification rule.; This rule will be used in the proving process.
	: the jurisdiction rule.; This rule will be used in the proving process.
	: the freshness-conjuncatenation rule.; This rule will be used in the proving process.