NAME
qsieve, qsafe
— generate system moduli
file
SYNOPSIS
qsieve |
[megabytes bits [initial]] |
qsafe |
[trials [generator]] |
DESCRIPTION
Theqsieve utility will list candidates for
Sophie-Germaine primes (where q = (p-1)/2) to standard output. The list is
checked against small known primes (less than 2**30). This step is both
processor and memory intensive.
The megabytes value sets a limit for the
internal sieve buffer. This should be small enough to remain entirely in
memory. Swap thrashing can increase the run time from hours to days or
weeks! When the megabytes value is zero (0),
qsieve will select a default suitable for the
bits.
The bits value sets the length of the generated possible primes (typically 768, 1024, 1536, 2048, 3072, or 4096, although others can be used for variety).
The optional initial value (hex) specifies
the beginning of the search. Otherwise, qsieve
generates a randomly selected number.
The qsafe utility will perform a
Miller-Rabin primality test on the list of candidates (checking both q and
p) from standard input. The result is a list of so-call "safe"
primes to standard output, suitable for use as Diffie-Hellman moduli. This
step is merely processor intensive.
The trials value sets the number of Miller-Rabin interations (typically 16 to 128).
The optional generator value (hex) limits
testing to candidates with a specific generator (usually 2). Otherwise,
qsafe will test each candidate and suggest a
generator.
SEE ALSO
HISTORY
These programs were originally developed for the Photuris project, and later the OpenSSH project.