Re: Random bitstring generation in PARI library

[Aleksandr Lenin <aleksandr.lenin@cyber.ee>]

On 03/27/2018 09:29 PM, Bill Allombert wrote:
> On Tue, Mar 27, 2018 at 02:41:46PM +0300, Aleksandr Lenin wrote:
>> Hello,
>>
>> what is the procedure to generate a random k-bit number, where k is
>> greater than BITS_IN_LONG?
> 
> In GP, random(2^k)
> 
>> Reading through the manual
>> (https://pari.math.u-bordeaux.fr/pub/pari/manuals/2.10.0/libpari.pdf) I
>> managed to find only pari_rand, random_bits, random_Fl which return an
>> (unsigned) long, and I need a bigger number. The function randomi indeed
>> returns a GEN, but in the range 1..p-1, but I need a random bitstring of
>> length k.
> 
> In C you can do randomi(int2n(k))

this would return me a number in the range [0,2^k-1], this is not
exactly what I need. I would like to be able to generate numbers of
k-bit length only.

> 
> Cheers,
> Bill.
> 

-- 
With kind regards,
Aleksandr