The authentication and key exchanging protocol for communication in the network(such as the internet) generating the random number and session key. Trusted party or server is communicating with all the participants.
2. • This protocol was presented to counter the suppress-replay attacks.
SUPPRESS – REPLAY ATTACKS:
Clock among the various participants be synchronized.
Mostly, clocks get out of sync due to system faults or by
sabotage.
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3. A and B are authenticating
and key exchanging with
the help of T.
T
A B
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4. Contd……
where,
𝑁𝑎 - A’s random number
𝑁𝑏 - B’s random number
𝐸 𝑘𝑏𝑡- Symmetric key shared T & B
𝑇𝑏 - Timestamp
𝐸 𝐾𝑎𝑡 - Symmetric key shared T & A
𝐾 𝑎𝑏 - Random Session Key
NOTE:
(i) A authenticate using 𝑵 𝒂 and extracts Kab.
(ii) B authenticate using 𝑻 𝒃 & 𝑵 𝒃value and extracts Kab.
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