Huge Cipher Text Size on CP-ABE

[svittal19]

Hi,

We happen to use this openabe library for one of our research works in networking. We used the example program test_cp.cpp for our trials. However, huge ciphertext size is causing the issue consuming high network bandwidth. We would like to know the smallest ciphertext size on CP-ABE for a single byte with a very simple policy ? Hoping for some help on this.

Thanks
Shwetha

[PekeDevil]

CP-ABE, by its nature, usually produces big ciphertext. If it's too much for the available bandwidth, you have some options:

• Choose a different CP-ABE scheme. OpenABE uses Waters11, which may not be the most efficient for you (either in size or time). In fact, un Waters 11 the size of the generated ciphertext is related to both the size of the original plaintext, and the complexity of the policy. So one can hardly define a minimum size.
• Choose a completely different scheme that does not belong to the ABE family.

In case you want to explore the first option, you will have to change libraries. Here you have a survey of many different libraries. If you do not want to read it, I can spoil it for you and say that Charm is the one that offers most options.