A Study Of Attribute-Based Encryption Defending Against Key Abuse Attacks

With the rapid development of the Internet, people give more consideration to the security of data stored in a distributed network, the traditional public ken encryption which belongs to one-to-one communication model has been unable to satisfy the need of people. Attribute-Based Encryption(ABE) is a new type of public key encryption and it supports multi-to-multi communication model. Data stored in a distributed network can be encrypted by ABE easily, and it has become a popular direction gradually.Firstly, the paper introduces the Attribute-Based Encryption, including Key-Policy Attribute-Based Encryption and Ciphertext-Policy Attribute-Based Encryption, both of them control the access rights by an access structure and a set of properties. Secondly, we introduce the problem of key abuse. And lastly, we construct a white-box traceable KP-ABE and a black-box traceable KP-ABE.1) In the scheme of the white-box traceable KP-ABE, the user needs to submit his ID to the authorities, and the ID will be embedded into the key in the key generation. The scheme can find out an illegal user by verifying the key have a standard format structure.We make further improvement for the scheme, using the technology of digital signature, what the user gives to the authority is not his ID, but the digital signature of his ID. The scheme is traceable both for the user and the authority.2) In the scheme of the black-box traceable KP-ABE, each bit of user ID is defined as an attribute, the set of attributes includes the normal attribute and the new attribute of user ID. The scheme is black-box traceable, we can find out an illegal user by observing the pirate device's outputs on certain inputs.The two solutions implemented in this paper have higher efficiency in key generation and decryption when compared with other solutions.