I'm familiar with LibTomMath. Tom St. Denis used to post to the comp.lang.c newsgroup years ago. Some 15 years ago I used it (or rather LibTomCrypt, which is based on it) in a commercial project to do some RSA-based authentication on some configuration packets sent to mobile devices.
I chose MPI for TXR; LibTomMath, though providing some optimizations like Karatsuba multiplication, just brings in too much cruft.
Quite a few bugs in MPI, but I have a handle on it.
I extended it with bit operations, a faster square root, more conversion routines and such.
http://www.kylheku.com/cgit/txr/log/mpi
I'm familiar with LibTomMath. Tom St. Denis used to post to the comp.lang.c newsgroup years ago. Some 15 years ago I used it (or rather LibTomCrypt, which is based on it) in a commercial project to do some RSA-based authentication on some configuration packets sent to mobile devices.