fentec-project/gofe

Functional encryption library in Go

gofe's Issues

How to convert key to short code

like this

I saw on this website: https://asecuritysite.com/encryption/go_abe

FE with authenticated encryption

Hi, sorry for open a issue to ask this, but I couldn't find other way to send a message to you. I would like to know if there is any construction in gofe that allows the use of FE with authenticated encryption capabilities? For instance, one could use something like DDH-MAC in a similar way that is done with AES?

Could we implement the paillier-based DMCFE?

cause, I find it hard to implement the KeyGen algorithm for paillier-based DMCFE described in ACK+19(Abdalla, Benhamouda, Kohlweiss, Waldner).

To implement it, we have to find a way to generate n random vectors v_i such that the sum of v_i is 0. And the v_i should be in Z_n^M. I suppose that we could use the DH key exchange just like in DDH-based DMCFE, and then hash Z_q^M to the Z_n^M, which may not be secure; otherwise, I don't know how to resolve it.

So, my question is: could we do it？ And if you think about implementing the paillier-based DMCFE?

Key serialization

Thanks for this awesome library!

Is it possible to serialize keys to a file? I didn't find any info about serialization.

Thanks in advance!

Algorithm implementation

Is there any implementation of CP-ABE encryption algorithm with MA‑CPABE with elliptic curve cryptography ? thanks

dependencies

Hi,

I'm very familiar with go, but I had in to install the following dependencies to avoid errors:

bn256
pkg/errors
stretchr/testify/assert

[FAME] Support for string instead of int in key attributes

The key attributes are ints today (gamma - https://github.com/fentec-project/gofe/blob/master/abe/fame.go#L231). This is a bit of a compatibility problem with existing data formats in software and is pretty restrictive :)

In my scenario, I want to pass UUID (a user can access multiple projects, each project already has a UUID, converting a 128 bit UUID to a 64-bit int would risk collision). It would seem useful to support a more generic data type such as a string (interface{} would force quite some work on reflection).

I've modified the code in my branch (which works all tests passes), but there are a few caveats.

• I'm no cryptography guru :)
• I moved each encryption in a separate package, make it easier to figure out boundaries (IMHO).
• GPSW and FAME share the same policy implementation, I haven't really looked at GPSW but seems to be there are some more int related checks (for example https://github.com/fentec-project/gofe/blob/master/abe/gpsw.go#L182)
• To solve the shared policy dependency, I added embedded structs (https://github.com/remiphilippe/gofe/blob/attrib-key-string/abe/fame/msp.go#L6 reduces the code changes)
• To keep GPSW working, I added a new RowToAttribI (https://github.com/remiphilippe/gofe/blob/attrib-key-string/abe/policy.go#L38), added a format parameter (int or string, should really be a const but it was a test https://github.com/remiphilippe/gofe/blob/attrib-key-string/abe/policy.go#L53) and redefined the BooleanToMSP per package (https://github.com/remiphilippe/gofe/blob/attrib-key-string/abe/gpsw/msp.go#L20 and https://github.com/remiphilippe/gofe/blob/attrib-key-string/abe/fame/msp.go#L20)

All this means introducing a breaking change due to the package change.

I have the working changes here: https://github.com/remiphilippe/gofe/tree/attrib-key-string/abe let me know what you think and if that's something we could look at merging (in some shape or form)?

Sans => Dufour Sans

Hi everyone,

I'm one of the authors of the quadratic FE and the IP DMCFE papers you implement; glad to see they have attracted interest. My family name is actually Dufour Sans, not Sans, but most academic software has a hard time figuring it out. Could you please correct the citations and the acronyms? That'd be very much appreciated.

Cheers,
Edouard

CP-ABE with hidden access policy

Is there any implementation of CP-ABE encryption algorithm with hidden access policy? thanks

How to calculate intermediate values in multi input scheme?

I followed the example given in the README file. I understood the Decrypt function returns the mod after executing decryption for number of Slots times. I am interested in how can I calculate intermediate values (c, OTPKey) defined in the Decrypt function. I put some debug logs in the function and checked the research paper but could not come up with formula.
Use following sample values.

X :  [ 3 3 4  2 3 2]
Y :  [ 1 2 1  1 0 1]
opt key:  [ 2 3 1  4 2 3]
c0:  2
c1:  1
OTPKey  1

Could someone explain how c0, c1 and OTPKey can be calculated ?