Research Article

A Secure and Anonymous Two-Factor Authentication Protocol in Multiserver Environment

Table 4

Notations in BAN logic.

believes , that is, the principal believes the statement is true.

sees , that is, the principal receives a message that contains .

has jurisdiction over , that is, the principal can generates or computes .

said , that is, the principal has sent a message containing .

is fresh, that is, 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 .

ā€‰: 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.