Description

Abstract

In Cipher text Policy Attribute Based Encryption (CP-ABE)a previously defined association

between the attributes of a user and the cipher text associated with these attributes is exploited to

determine the secret key of the user. However, for a user with multiple attributes, the length of the

key depends on the number of attributes. The existing methods that use reasonably computable

decryption policies produce the ciphertext of size at least linearly varying with the number of

attributes. In this paper, we propose two schemes. One scheme is of variable length based on Be

then court et al. construction.