可实现固定用户安全访问移动终端外包数据的非对称代理重加密系统

为实现固定用户安全共享移动终端的加密数据，提出了跨加密系统的非对称代理重加密系统。在该系统中，计算能力有限的移动终端使用相对简单的基于身份的加密系统，而服务器和固定用户使用较复杂的基于身份的广播加密系统。该系统基于密文转换机制，使移动终端简单的IBE密文被代理者转换成复杂的IBBE密文，同时代理者不会得知明文的任何信息。该方案的安全性可以归约到底层的IBE和IBBE方案的安全性。理论和实验分析表明，该方案可实现移动终端只需很少的资源便能让固定用户安全地共享其加密数据。

Asymmetric proxy re-encryption system achievable for office user to securely sharing outsourcing data of mobile terminal

In order to realize the office users securely share encrypted data of the mobile terminal,an asymmetric cross-cryptosystem proxy re-encryption system is proposed.In this system,mobile terminals who have the limited computing power use relatively simple identity-based encryption system,while the server and office users use more complex identity-based broadcast encryption system.This system is based on the ciphertext conversion mechanism,which enables the simple IBE ciphertext of mobile terminal to be converted into the complex IBBE ciphertext by proxy while the proxy know nothing of the plaintext.The security of this scheme can be reduced to the safety of the IBE and IBBE scheme.Theoretical and experimental analysis indicate that the scheme is useful for the mobile ter-minal to consume less resources to make the fixed users share the data encrypted by mobile terminal,and it is more practical.