With the growth of technology most of the sensitive data transactions are happening over the internet, which has to be protected against unauthorized access. The design and development of a Secure Hardware Token (SHT), is explained in this paper, which will protect the sensitive data from most of the threats, As it generates the highly secure onetime passwords (Time based OTP) [2] ensuring that only legitimate users are authorized to access sensitive data/applications and the SHT will perform cryptographic functionalities [7] like Key Generation (RSA), Digital Signature creation, Signature verification, Encryption, Decryption & Hashing techniques. Since all the functionalities are happening in Hardware token there is no risk of Operating System dependent vulnerabilities. SHT will also act as secure USB Storage device, which stores Private Key of the respective user securely. In this paper, a Secure Mail application is shown, which makes use of SHT to perform authentication of the user(for login with OTP) to do all the cryptographic operations for Secure mail application system. Such types of applications are needed where highly confidential data flows across the public network.