tommath/changes.txt

July 12th, 2003
v0.23  -- Optimized mp_prime_next_prime() to not use mp_mod [via is_divisible()] in each
          iteration.  Instead now a smaller table is kept of the residues which can be updated
          without division.
       -- Fixed a bug in next_prime() where an input of zero would be treated as odd and
          have two added to it [to move to the next odd].
       -- fixed a bug in prime_fermat() and prime_miller_rabin() which allowed the base
          to be negative, zero or one.  Normally the test is only valid if the base is
          greater than one.
       -- changed the next_prime() prototype to accept a new parameter "bbs_style" which
          will find the next prime congruent to 3 mod 4.  The default [bbs_style==0] will
          make primes which are either congruent to 1 or 3 mod 4.
       -- fixed mp_read_unsigned_bin() so that it doesn't include both code for
          the case DIGIT_BIT < 8 and >= 8
       -- optimized div_d() to easy out on division by 1 [or if a == 0] and use
          logical shifts if the divisor is a power of two.
       -- the default DIGIT_BIT type was not int for non-default builds.  Fixed.

July 2nd, 2003
v0.22  -- Fixed up mp_invmod so the result is properly in range now [was always congruent to the inverse...]
       -- Fixed up s_mp_exptmod and mp_exptmod_fast so the lower half of the pre-computed table isn't allocated
          which makes the algorithm use half as much ram.
       -- Fixed the install script not to make the book :-) [which isn't included anyways]
       -- added mp_cnt_lsb() which counts how many of the lsbs are zero
       -- optimized mp_gcd() to use the new mp_cnt_lsb() to replace multiple divisions by two by a single division.
       -- applied similar optimization to mp_prime_miller_rabin().
       -- Fixed a bug in both mp_invmod() and fast_mp_invmod() which tested for odd
          via "mp_iseven() == 0" which is not valid [since zero is not even either].

June 19th, 2003
v0.21  -- Fixed bug in mp_mul_d which would not handle sign correctly [would not always forward it]
       -- Removed the #line lines from gen.pl [was in violation of ISO C]       

June 8th, 2003
v0.20  -- Removed the book from the package.  Added the TDCAL license document.  
       -- This release is officially pure-bred TDCAL again [last officially TDCAL based release was v0.16]

June 6th, 2003
v0.19  -- Fixed a bug in mp_montgomery_reduce() which was introduced when I tweaked mp_rshd() in the previous release.
          Essentially the digits were not trimmed before the compare which cause a subtraction to occur all the time.
       -- Fixed up etc/tune.c a bit to stop testing new cutoffs after 16 failures [to find more optimal points]. 
          Brute force ho!
          

May 29th, 2003
v0.18  -- Fixed a bug in s_mp_sqr which would handle carries properly just not very elegantly.
          (e.g. correct result, just bad looking code)
       -- Fixed bug in mp_sqr which still had a 512 constant instead of MP_WARRAY
       -- Added Toom-Cook multipliers [needs tuning!]
       -- Added efficient divide by 3 algorithm mp_div_3
       -- Re-wrote mp_div_d to be faster than calling mp_div 
       -- Added in a donated BCC makefile and a single page LTM poster (ahalhabsi@sbcglobal.net)
       -- Added mp_reduce_2k which reduces an input modulo n = 2**p - k for any single digit k
       -- Made the exptmod system be aware of the 2k reduction algorithms.
       -- Rewrote mp_dr_reduce to be smaller, simpler and easier to understand.

May 17th, 2003
v0.17  -- Benjamin Goldberg submitted optimized mp_add and mp_sub routines.  A new gen.pl as well
          as several smaller suggestions.  Thanks!
       -- removed call to mp_cmp in inner loop of mp_div and put mp_cmp_mag in its place :-)
       -- Fixed bug in mp_exptmod that would cause it to fail for odd moduli when DIGIT_BIT != 28
       -- mp_exptmod now also returns errors if the modulus is negative and will handle negative exponents
       -- mp_prime_is_prime will now return true if the input is one of the primes in the prime table
       -- Damian M Gryski (dgryski@uwaterloo.ca) found a index out of bounds error in the 
          mp_fast_s_mp_mul_high_digs function which didn't come up before.  (fixed) 
       -- Refactored the DR reduction code so there is only one function per file.
       -- Fixed bug in the mp_mul() which would erroneously avoid the faster multiplier [comba] when it was
          allowed.  The bug would not cause the incorrect value to be produced just less efficient (fixed)
       -- Fixed similar bug in the Montgomery reduction code.
       -- Added tons of (mp_digit) casts so the 7/15/28/31 bit digit code will work flawlessly out of the box. 
          Also added limited support for 64-bit machines with a 60-bit digit.  Both thanks to Tom Wu (tom@arcot.com)
       -- Added new comments here and there, cleaned up some code [style stuff]
       -- Fixed a lingering typo in mp_exptmod* that would set bitcnt to zero then one.  Very silly stuff :-)
       -- Fixed up mp_exptmod_fast so it would set "redux" to the comba Montgomery reduction if allowed.  This
          saves quite a few calls and if statements.
       -- Added etc/mont.c a test of the Montgomery reduction [assuming all else works :-| ]
       -- Fixed up etc/tune.c to use a wider test range [more appropriate] also added a x86 based addition which
          uses RDTSC for high precision timing.  
       -- Updated demo/demo.c to remove MPI stuff [won't work anyways], made the tests run for 2 seconds each so its 
          not so insanely slow.  Also made the output space delimited [and fixed up various errors]
       -- Added logs directory, logs/graph.dem which will use gnuplot to make a series of PNG files 
          that go with the pre-made index.html.  You have to build [via make timing] and run ltmtest first in the 
          root of the package.
       -- Fixed a bug in mp_sub and mp_add where "-a - -a" or "-a + a" would produce -0 as the result [obviously invalid].  
       -- Fixed a bug in mp_rshd.  If the count == a.used it should zero/return [instead of shifting]
       -- Fixed a "off-by-one" bug in mp_mul2d.  The initial size check on alloc would be off by one if the residue
          shifting caused a carry.  
       -- Fixed a bug where s_mp_mul_digs() would not call the Comba based routine if allowed.  This made Barrett reduction
          slower than it had to be.
          
Mar 29th, 2003
v0.16  -- Sped up mp_div by making normalization one shift call
       -- Sped up mp_mul_2d/mp_div_2d by aliasing pointers :-)
       -- Cleaned up mp_gcd to use the macros for odd/even detection
       -- Added comments here and there, mostly there but occasionally here too.

Mar 22nd, 2003
v0.15  -- Added series of prime testing routines to lib
       -- Fixed up etc/tune.c
       -- Added DR reduction algorithm
       -- Beefed up the manual more.
       -- Fixed up demo/demo.c so it doesn't have so many warnings and it does the full series of
          tests
       -- Added "pre-gen" directory which will hold a "gen.pl"'ed copy of the entire lib [done at
          zipup time so its always the latest]
       -- Added conditional casts for C++ users [boo!]

Mar 15th, 2003
v0.14  -- Tons of manual updates
       -- cleaned up the directory
       -- added MSVC makefiles
       -- source changes [that I don't recall]
       -- Fixed up the lshd/rshd code to use pointer aliasing
       -- Fixed up the mul_2d and div_2d to not call rshd/lshd unless needed
       -- Fixed up etc/tune.c a tad
       -- fixed up demo/demo.c to output comma-delimited results of timing
          also fixed up timing demo to use a finer granularity for various functions
       -- fixed up demo/demo.c testing to pause during testing so my Duron won't catch on fire
          [stays around 31-35C during testing :-)]
       
Feb 13th, 2003
v0.13  -- tons of minor speed-ups in low level add, sub, mul_2 and div_2 which propagate 
          to other functions like mp_invmod, mp_div, etc...
       -- Sped up mp_exptmod_fast by using new code to find R mod m [e.g. B^n mod m]
       -- minor fixes

Jan 17th, 2003
v0.12  -- re-wrote the majority of the makefile so its more portable and will
          install via "make install" on most *nix platforms
       -- Re-packaged all the source as seperate files.  Means the library a single
          file packagage any more.  Instead of just adding "bn.c" you have to add
          libtommath.a
       -- Renamed "bn.h" to "tommath.h"
       -- Changes to the manual to reflect all of this
       -- Used GNU Indent to clean up the source

Jan 15th, 2003
v0.11  -- More subtle fixes
       -- Moved to gentoo linux [hurrah!] so made *nix specific fixes to the make process
       -- Sped up the montgomery reduction code quite a bit
       -- fixed up demo so when building timing for the x86 it assumes ELF format now
       
Jan 9th, 2003
v0.10  -- Pekka Riikonen suggested fixes to the radix conversion code.  
       -- Added baseline montgomery and comba montgomery reductions, sped up exptmods
          [to a point, see bn.h for MONTGOMERY_EXPT_CUTOFF]
       
Jan 6th, 2003
v0.09  -- Updated the manual to reflect recent changes.  :-)
       -- Added Jacobi function (mp_jacobi) to supplement the number theory side of the lib
       -- Added a Mersenne prime finder demo in ./etc/mersenne.c

Jan 2nd, 2003
v0.08  -- Sped up the multipliers by moving the inner loop variables into a smaller scope
       -- Corrected a bunch of small "warnings"
       -- Added more comments
       -- Made "mtest" be able to use /dev/random, /dev/urandom or stdin for RNG data
       -- Corrected some bugs where error messages were potentially ignored
       -- add etc/pprime.c program which makes numbers which are provably prime.
       
Jan 1st, 2003
v0.07  -- Removed alot of heap operations from core functions to speed them up
       -- Added a root finding function [and mp_sqrt macro like from MPI]
       -- Added more to manual 

Dec 31st, 2002
v0.06  -- Sped up the s_mp_add, s_mp_sub which inturn sped up mp_invmod, mp_exptmod, etc...
       -- Cleaned up the header a bit more
       
Dec 30th, 2002
v0.05  -- Builds with MSVC out of the box
       -- Fixed a bug in mp_invmod w.r.t. even moduli
       -- Made mp_toradix and mp_read_radix use char instead of unsigned char arrays
       -- Fixed up exptmod to use fewer multiplications
       -- Fixed up mp_init_size to use only one heap operation
          -- Note there is a slight "off-by-one" bug in the library somewhere
             without the padding (see the source for comment) the library 
             crashes in libtomcrypt.  Anyways a reasonable workaround is to pad the
             numbers which will always correct it since as the numbers grow the padding
             will still be beyond the end of the number
       -- Added more to the manual
       
Dec 29th, 2002
v0.04  -- Fixed a memory leak in mp_to_unsigned_bin
       -- optimized invmod code
       -- Fixed bug in mp_div
       -- use exchange instead of copy for results
       -- added a bit more to the manual
       
Dec 27th, 2002
v0.03  -- Sped up s_mp_mul_high_digs by not computing the carries of the lower digits
       -- Fixed a bug where mp_set_int wouldn't zero the value first and set the used member.
       -- fixed a bug in s_mp_mul_high_digs where the limit placed on the result digits was not calculated properly
       -- fixed bugs in add/sub/mul/sqr_mod functions where if the modulus and dest were the same it wouldn't work
       -- fixed a bug in mp_mod and mp_mod_d concerning negative inputs
       -- mp_mul_d didn't preserve sign
       -- Many many many many fixes
       -- Works in LibTomCrypt now :-)
       -- Added iterations to the timing demos... more accurate.
       -- Tom needs a job.       

Dec 26th, 2002
v0.02  -- Fixed a few "slips" in the manual.  This is "LibTomMath" afterall :-)
       -- Added mp_cmp_mag, mp_neg, mp_abs and mp_radix_size that were missing.
       -- Sped up the fast [comba] multipliers more [yahoo!]

Dec 25th,2002
v0.01  -- Initial release.  Gimme a break.
       -- Todo list, 
           add details to manual [e.g. algorithms]
           more comments in code
           example programs