This software is a Java realization for "ciphertext-policy attribute based encryption" (CP-ABE). To use this software, you will need to have the Java Pairing Based Cryptography Library(jPBC) installed (jpbc-1.2.0 is tested). You can get it from the following page: http://gas.dia.unisa.it/projects/jpbc/ For more information on CP-ABE and a tutorial on using the tools, see the project homepage: http://junwei-wang.github.io/cpabe/ Your mush be responsible for the problem caused by using the code. I stop developping this package since July, 2012. A lot of issues are in this implementation. Feel free to contribute to and imporve this project since someone else may come across the same issue as you.