Obfuscation for multi-use re-encryption and its application in cloud computing

摘要

With the rapid development of cloud computing, more and more data are being centralized into cloud serverrnfor sharing. It is a challenge problem on how to keep them both private and accessible. Re-encryptionrnfunction is a useful tool to fulfill secure cloud computing. Cloud data owners store their encrypted data on therncloud server. When other cloud users want to share the cloud data, cloud server can re-encrypt the encryptedrndata for them. So data on the cloud server can be both accessible and private. Secure obfuscation for reencryptionrnfunction can hide all the private information in the re-encryption function, so the obfuscatedrnprogram can be directly outsourced to cloud server without leaking anything about the computation task.rnIn this paper, we study on secure obfuscation for three kinds of new re-encryption functions: multi-usernre-encryption, conditional re-encryption with keyword search, and broadcast re-encryption. We utilize thernobfuscated results as tools to fulfill secure cloud computing. Cloud-computing schemes based on obfuscationrnhave better security compared with other tools.