Data Encryption In The Network Environment

While the E-commerce has become more and more important in trade, the e-security is becoming a critical problem of it. The Encryption and Digital signature is the cut-edge research field in the e-security sector. This thesis introduce the PKI theory and explore the implement of information security under Internet environment. The thesis was divided in four parts: the generation and management of digital certification, utilizing of Public system, utilizing of digital signature, the establishment of SSL secure tune. I discussed the problems from the view of theory and implement under Java language, and explore a practical way to realize the goal.There are two ways to encrypt the data: Symmetric Algorithm Encryption, Public-key Algorithm Encryption. The Symmetric Algorithm can encrypt and decrypt very fast, while it's secret key has to be shared by the two sides; the Public-key Algorithm needn't to transfer the shared secret key, but encrypt/decrypt much slowly compared with the Symmetric Algorithm. In practice, we have to combine two methods to meet the requirement under Internet environment: to encrypt the plain text with the symmetric Algorithm and to encrypt the secret key with public-key Algorithm.In the PKI system, we have to store the public key and private key with certificate and private key information standard respectively. In this project, we store the public key with X.509 certificate and the private key with PKCS#8 standard. All these operations were implement by IAIK JCE class library.Digital Signature is an important method to secure the information over Internet. It can authenticate the identification of the participant of e-commerce. In this project, I usr the MD5 as it's digest Algorithm and SHA-1 as it's Digital Signature Algorithm, and implement it with SUN Javax class library.In the project, all the data are transfer by SSL secure tune.