폐기 및 추가가 자유로운 속성기반 암호

Abstract

Today’s computing technologies like the Cloud Computing have attracted more and more people to store their private data on Clouds. When people enjoy the advantages that are ease of sharing and cost saving, their concerns about data security also arise. For resolving this, encryption is needed for data saving in un-trusted storage. However, traditional encryption methods are not support fine-grained access control for encrypted data. CP-ABE (Ciphertext-Policy Attribute Based Encryption) is a kind of ABE(Attribute-Based Encryption) that was proposed to resolve the exact issue of fine-grained access control on shared data in un-trusted storage. There is essential issue when directly applying CP-ABE schemes to practical applications. It is user management like user revocation or user addition. In this paper, I proposed a new ABE scheme that the authority can invite new members to join or permanently revoke undesired members dynamically with general expressiveness of access structure.