Change curve

[cnasikas]

Hi!

Is it possible to change the curve ie from BN128 to ALT_BN128 without modifying the pequin files ? Like -DCURVE=ALT_BN128 ?

Thanks in advanced

[maxhowald]

According to libsnark's documentation here, you'll need to rebuild libsnark with cmake -DCURVE=ALT_BN128.

Note, libsnark is built and installed as part of the pepper setup process at the end of this script.

Finally, add the appropriate flag to our Makefile here:

pequin/pepper/Makefile

Lines 3 to 5 in c9417e8

	# according to libsnark's documentation, we need to use the same conditional defines libsnark was compiled with, as found in
	# thirdparty/libsnark/build/libsnark/CMakeFiles/snark.dir/flags.make
	CXXFLAGS = -m64 -std=c++11 -DCURVE_BN128 -DBN_SUPPORT_SNARK -DBINARY_OUTPUT -DMONTGOMERY_OUTPUT -DNO_PROCPS -DUSE_ASM

[cnasikas]

Thanks a lot for your answer. I am aware of the process you mentioned. I was wondering if it is possible to do it without modifying peppers's Makefile or installation script (probably not).

Thanks a lot!!

P.S: Feel free to close this issue if there is no alternative for the moment