EKE (Encrypted Key Exchange)

• Uses weak secret from password
• Works against dictionary attacks

• Provides perfect forward secrecy

Security features of EKE

• Authentication of Alice - Only a person with correct password will be able to get g^bmodp and get the shared key. Bob authenticates Alice by checking that Alice encrypted his challenge C1 using the correct key

• Authentication of Bob - Only a valid bob can encrypt the challenges properly.

• Security against Dictionary Attacks - Random password + DLP

Augmented Strong Password

• A person with W will be able to interpret messages
• Store a value in the server, derived from the original password