Zero-Knowledge Password Proof is often abbreviated as [[ZKPP]]. In a ZKPP, the user and the verifier engage in a series of interactions to prove the knowledge of the password. The protocol works as follows: 1. Initialization: The user and verifier agree on a set of parameters, such as a cryptographic hash function or encryption scheme. 2. Commitment: The user computes a commitment value based on their password without revealing it. This commitment is sent to the verifier. 3. Challenge: The verifier randomly selects a challenge, typically a random value or string, and sends it to the user. 4. Response: The user uses their password to compute a response based on the challenge and sends it back to the verifier. 5. Verification: The verifier uses the commitment value, challenge, and response to verify if the user has proven knowledge of the correct password. The key concept behind ZKPP is that even if an attacker intercepts all communication between the user and verifier, they cannot determine the actual password from this information alone. This is because each interaction reveals only partial information about the password while keeping it hidden. ZKPP provides several advantages over traditional authentication methods: 1. Privacy: Since the actual password is never revealed during authentication, there is no risk of it being intercepted or stolen by attackers. 2. Security against offline attacks: Even if an attacker obtains all communication exchanged during authentication, they cannot use this information to determine the actual password. 3. Resistance against replay attacks: ZKPP incorporates random challenges for each authentication attempt, preventing attackers from reusing previously intercepted responses. 4. User convenience: ZKPP can be designed in such a way that it does not require users to remember complex passwords, as the protocol itself ensures the security of the authentication process. Overall, ZKPP provides a strong and secure method for password-based authentication while preserving user privacy and preventing password exposure. It is widely used in various applications where security and privacy are critical.