Patent ID: 7861096

Claim:
A computer controlled method for revealing sensitive information in a selectively encrypted data unit comprising: accessing said selectively encrypted data unit, comprising an encrypted version of said sensitive information, an attribute vector associated with said encrypted version, and a plurality of auxiliary values computed directly using the attribute vector and a random number, said encrypted version capable of being decrypted into said sensitive information; accessing a unique capability key, said unique capability key associated with a key descriptor which is determined based at least on part on the attribute vector, said unique capability key responsive to one or more cryptosystem parameters, one or more random numbers and one or more shares; determining whether said attribute vector is filtered by said key descriptor; acquiring, responsive to determining, a protection key responsive to said cryptosystem parameters, said plurality of auxiliary values, said key descriptor and said unique capability key; decrypting the encrypted version with said protection key to generate said sensitive information; and presenting said sensitive information.