Smart card secure channel protocols based on public key cryptography are not widely utilised mainly due to processing overheads introduced in the underlying smart card microprocessors and the complexities introduced by the operation of a PKI infrastructure. In this paper we analyse the significance of public key secure channel protocols in multi-application smart cards. We believe that multi-application smart card technology (e.g. the GlobalPlatform smart card specification) should benefit more from the advantages of public key cryptography specifically for the initiation and maintenance of a secure channel. This paper introduces a public key based cryptographic protocol for secure entity authentication, data integrity and data confidentiality. The proposed secure channel protocol uses a combination of public key, secret key and the main idea behind the Diffie-Hellman key establishment protocols in order to achieve the desired goals.