News Archive 8

Minor fixes: applied John Bethencourt’s patch to address bugs that arose on 64-bit machines, added some comments from Dmitry Kosolapov, resolved a naming conflict that should solve compilation problems in some cases.

The official PBC library URL is now

which means PBC is hosted by a department webserver rather than my personal office machine. However, the git repository still lives on my system.

I’ll try to keep the old URLs working for a while.

I reordered the arguments to element_from_hash(). It seems to be standard to pass the length of a buffer after the pointer to the buffer. This is incompatible with older versions of the library.

I renamed quan.c (contributed by Dmitry Kosolapov) to yuanli.c and removed workarounds that are not needed anymore.

I fixed a bug in element_init_same_as() (reported by John Bethencourt).

I also implemented some discrete log algorithms (brute force, Pollard rho and index calculus for some cases), but these aren’t documented.

I added the element_mul_zn() function so using additive notation for groups matches multiplicative notation better.

I changed how element_from_hash() and element_to_bytes() work. They are incompatible with older versions of PBC.

By default, PBC now tries to use /dev/urandom for random number generation. If this fails, it prints a warning and falls back to a deterministic random number generator.

Dmitry Kosolapov contributed quan.c (in the test subdirectory), which demonstrates the scheme described in this paper.

The previous release accidentally omitted a certain header file, due to a problem with Makefile.am.

Preprocessing for A1 pairings was implemented.

I was a little surprised because I have a script named makerelease that performs basic sanity checks when I release new versions. But then I realized my script only checks building from a git export, not from a tarball built by the autotools.

To avoid these sorts of problems in the future, I rewrote my script to create the tarball from the git tree, rather than rely on make dist. I’m not very good with the autotools, and for me it is much more important that the git repository contains every file.