This paper introduces designated verifier proofs, which allow a proof to convince only the designated verifier, ensuring privacy while maintaining authenticity. The concept is applied to undeniable signatures, where only the intended verifier can be convinced of a signature's validity. The solution uses trap-door commitments, enabling the designated verifier to open commitments in any way. This method allows both interactive and non-interactive designated verifier proofs, combining the properties of ordinary signatures and undeniable signatures. The paper discusses the importance of verifying messages and off-the-record messages, showing how they can be combined using designated verifiers. It also addresses attacks such as blackmail and mafia attacks, where the conviction is transferred to hidden co-verifiers. The solution ensures that only the specified verifier can be convinced by the proof, even if they share secret information. The paper presents a method to transform three-move zero-knowledge protocols into non-interactive designated verifier proofs. It also discusses the extension of the concept to multiple designated verifiers, where each verifier can be convinced by the proof without being able to convince others. Practical issues are addressed, including ensuring that the designated verifier can simulate identical transcripts and preventing the transfer of conviction to unauthorized parties. The paper concludes that designated verifier proofs provide a balance between privacy and authenticity, allowing authenticated but private conversations. It also highlights the importance of strong designated verifiers, where the verifier is assumed to be honest and follows the prescribed protocols. The paper references various cryptographic techniques and previous works, emphasizing the significance of the proposed solution in enhancing security and privacy in digital communications.This paper introduces designated verifier proofs, which allow a proof to convince only the designated verifier, ensuring privacy while maintaining authenticity. The concept is applied to undeniable signatures, where only the intended verifier can be convinced of a signature's validity. The solution uses trap-door commitments, enabling the designated verifier to open commitments in any way. This method allows both interactive and non-interactive designated verifier proofs, combining the properties of ordinary signatures and undeniable signatures. The paper discusses the importance of verifying messages and off-the-record messages, showing how they can be combined using designated verifiers. It also addresses attacks such as blackmail and mafia attacks, where the conviction is transferred to hidden co-verifiers. The solution ensures that only the specified verifier can be convinced by the proof, even if they share secret information. The paper presents a method to transform three-move zero-knowledge protocols into non-interactive designated verifier proofs. It also discusses the extension of the concept to multiple designated verifiers, where each verifier can be convinced by the proof without being able to convince others. Practical issues are addressed, including ensuring that the designated verifier can simulate identical transcripts and preventing the transfer of conviction to unauthorized parties. The paper concludes that designated verifier proofs provide a balance between privacy and authenticity, allowing authenticated but private conversations. It also highlights the importance of strong designated verifiers, where the verifier is assumed to be honest and follows the prescribed protocols. The paper references various cryptographic techniques and previous works, emphasizing the significance of the proposed solution in enhancing security and privacy in digital communications.