Improved PGP Secure E-mail System

【Abstract】USB device can be used as a USB security key. When it is used as an identity token in an network Identity(ID) authentication system, adopting the correspondence of the USB security key is more safe than having no adoptive correspondence. By introducing the concept of N-dimensional security key and combining a two-way USB security key authentication protocol, this paper proposes an improved PGP e-mail system. Making use of the USB security key to carry on an identity attestation and manage with airtight key while carrying out safety correspondence, this system does not need the help of trusted third party. Experimental result shows that the system resists man-in-the-middle attack and interleaving attack. 【Key words】encryption; USB security key; Identity(ID) authentication