New to PARI/GP.. How to use PARI/GP for with h(p-1/q) mod p

Question

I am currently making a script for digital signature algorithm until I met a stumbling block which with a lot of trial and errors, I still can't get through it.

There are 3 integers which is stored to p,q,h.

Using the above 3, I would like to do

 g = h(p-1/q) mod p

The number of things I tried in my .gp script:

 1. g = mod((h(p-1)/q),p);

 2. g = h((p-1)/q) mod p;

 3. temp = h(p-1/q);
    g = mod(temp,p);

They all can't work and have errors. Anyone can enlighten me on using PARI/GP?

score 1 · Accepted Answer · answered Apr 07 '14 at 16:59

1

1. was almost correct: you're missing a multiplication sign *, and the function name is Mod, not mod.

Try

g = Mod(h*(p-1)/q, p)

answered Apr 07 '14 at 16:59

K.B.

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Though if the OP wants an integer rather than something of type `Mod`, something like `(h * (p-1) / q) % p` might work better. – Mark Dickinson Apr 07 '14 at 17:05
You can also use `lift` to convert an INTMOD like Mod(3, 7) to a number like 3. – Charles Apr 21 '15 at 18:35

New to PARI/GP.. How to use PARI/GP for with h(p-1/q) mod p

1 Answers1