From bd9fe9759eb3c67210542757ef374d09730626ae Mon Sep 17 00:00:00 2001 From: Mark Wooding Date: Thu, 11 May 2017 10:42:15 +0100 Subject: [PATCH] math/strongprime.c: Improve the commentary. --- math/strongprime.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/math/strongprime.c b/math/strongprime.c index 5b136534..a12c0d0a 100644 --- a/math/strongprime.c +++ b/math/strongprime.c @@ -121,7 +121,10 @@ mp *strongprime_setup(const char *name, mp *d, pfilt *f, unsigned nbits, rabin_iters(nb), pgen_test, &rb)) == 0) goto fail_t; - /* --- Choose a suitable value for %$r = 2it + 1$% for some %$i$% --- */ + /* --- Choose a suitable value for %$r = 2it + 1$% for some %$i$% --- * + * + * Then %$r \equiv 1 \pmod{t}$%, i.e., %$r - 1$% is a multiple of %$t$%. + */ rr = mp_lsl(rr, t, 1); pfilt_create(&c.f, rr); @@ -137,7 +140,12 @@ mp *strongprime_setup(const char *name, mp *d, pfilt *f, unsigned nbits, /* --- Select a suitable congruence class for %$p$% --- * * - * This computes %$p_0 = 2 s (s^{r - 2} \bmod r) - 1$%. + * This computes %$p_0 = 2 s (s^{-1} \bmod r) - 1$%. Then %$p_0 + 1$% is + * clearly a multiple of %$s$%, and + * + * %$p_0 - 1 \equiv 2 s s^{-1} - 2 \equiv 0 \pmod{r}$% + * + * is a multiple of %$r$%. */ rr = mp_modinv(rr, s, q); -- 2.11.0