关键词: 受控文档, 基于身份的加密, 透明加密, 文档安全, 访问控制

Abstract: To deal with the increasingly serious situation of document's security and better protect the controlled documents, in this paper, an identity-based On-The-Fly Encryption (OTFE) and decryption scheme was proposed for the controlled documents, which combined an Identity-Based Encryption (IBE) algorithm with an on-the-fly encryption technique. In the scheme, file system filter driver technology was used to monitor program's behaviors on the controlled documents; meanwhile, the IBE algorithm was used to encrypt and decrypt the controlled documents. Specifically, a new algorithm that associated the original ciphertext and divided the associated ciphertext into two parts stored in different locations was proposed. Therefore, it is impossible for an adversary to obtain the whole ciphertext and further recover the original plaintext. Finally, an elaborate description was made on the scheme from system level and algorithm level. The security analysis indicates that the proposed scheme is able to effectively protect the controlled documents.

Key words: controlled document, identity-based encryption, On-The-Fly Encryption (OTFE), document security, access control