说明：  完成基于非对称密码技术的对称密钥分配工作 说明： （1）在完成上述基于公钥证书的非对称密钥分配工作的基础上，根据教材上基于非对称密码技术的对称密钥分配方案，完成对称密钥Ks的分配工作。 （2）A用Ks对一图象文件（test_pic.bmp)进行加密并发送给B，B收到后解密，对比原图象看是否一致，并记录整个加密/解密的所用时间T2； （3）对比T1和T2； 要求： （1）JAVA语言编程实现，基于RSA完成非对称密码技术的加/解密，基于DES完成对称密码技术的加/解密（JAVA有库函数支持）； （2）通信内容为一图象文件（test_pic.bmp)； （3）基于网络完成密钥分配工作（作为通信的双方A、B应部署于两台主机上）； （4）所分配的对称密钥皆为一次一密，随机产生； （5）具体密钥分配过程请以课本中基于非对称密码技术的对称密钥分配方案为参考，完成从步骤1到步骤4的全过程；
(Completed based on asymmetric cryptography symmetric key distribution work Description: ( 1 ) Upon completion of the above-mentioned asymmetric public key certificate-based key distribution based on the work , according to the materials on asymmetric cryptography-based symmetric key distribution scheme , the completion of the distribution of symmetric key Ks work . (2) A use of an image file Ks (test_pic.bmp) is encrypted and sent to B, B to decrypt after receipt , compared to see if the same original image , and records the encryption/decryption used time T2 ( 3 ) comparing T1 and T2 Requirements: (1) JAVA programming language, based on the RSA asymmetric cryptographic techniques to complete encryption/decryption , based on the DES symmetric cryptographic techniques to complete the encryption/decryption (JAVA library functions are supported ) ( 2) The content of the communication is an image file (test_pic.bmp) ( 3 ) complete network-based key distribution job ( as the )