This paper presents a three-party variation of the Diffie-Hellman protocol using Weil and Tate pairings on elliptic curves. The protocol allows three participants to establish a common secret in a single round of communication. The key idea is to use pairings to transform the discrete logarithm problem on elliptic curves into a discrete logarithm problem in a finite field, enabling efficient key exchange. The protocol is based on the properties of elliptic curve pairings, which allow for the construction of a common secret through a series of mathematical operations involving points on the curve. The paper discusses the use of pairings in cryptographic applications, particularly in reducing the discrete logarithm problem on elliptic curves to a discrete logarithm problem in a finite field. It also addresses the security implications of using such pairings, including the hardness of the discrete logarithm problem in the chosen finite field and the difficulty of solving the decision Diffie-Hellman problem. The tripartite Diffie-Hellman protocol is described in detail, with a focus on the use of two points on the elliptic curve to ensure the security and efficiency of the protocol. The paper also explores the use of a single point approach, which requires careful selection of parameters to ensure the non-degeneracy of the pairing and the security of the protocol. The paper concludes by discussing the security assumptions and their relationships in pairing-based cryptography, emphasizing the importance of ensuring the hardness of the discrete logarithm problem in both the elliptic curve and the finite field used in the protocol. The paper also highlights the potential vulnerabilities and the need for careful parameter selection to ensure the security of the protocol.This paper presents a three-party variation of the Diffie-Hellman protocol using Weil and Tate pairings on elliptic curves. The protocol allows three participants to establish a common secret in a single round of communication. The key idea is to use pairings to transform the discrete logarithm problem on elliptic curves into a discrete logarithm problem in a finite field, enabling efficient key exchange. The protocol is based on the properties of elliptic curve pairings, which allow for the construction of a common secret through a series of mathematical operations involving points on the curve. The paper discusses the use of pairings in cryptographic applications, particularly in reducing the discrete logarithm problem on elliptic curves to a discrete logarithm problem in a finite field. It also addresses the security implications of using such pairings, including the hardness of the discrete logarithm problem in the chosen finite field and the difficulty of solving the decision Diffie-Hellman problem. The tripartite Diffie-Hellman protocol is described in detail, with a focus on the use of two points on the elliptic curve to ensure the security and efficiency of the protocol. The paper also explores the use of a single point approach, which requires careful selection of parameters to ensure the non-degeneracy of the pairing and the security of the protocol. The paper concludes by discussing the security assumptions and their relationships in pairing-based cryptography, emphasizing the importance of ensuring the hardness of the discrete logarithm problem in both the elliptic curve and the finite field used in the protocol. The paper also highlights the potential vulnerabilities and the need for careful parameter selection to ensure the security of the protocol.