Singular Manual: PocklingtonLehmer

| #### D.12.2.20 PocklingtonLehmer Procedure from library `crypto.lib` (see crypto_lib). Usage: PocklingtonLehmer(N); optional: PocklingtonLehmer(N,L); L a list of the first k primes Return: message N is not prime or {A,{p},{a_p}} as certificate for N being prime Note: assumes that it is possible to factorize N-1=A*B such that gcd(A,B)=1, the factorization of A is completely known and A^2>N . N is prime if and only if for each prime factor p of A we can find a_p such that a_p^(N-1)=1 mod N and gcd(a_p^((N-1)/p)-1,N)=1 Example:
    LIB "crypto.lib";
    bigint N=105554676553297;
    PocklingtonLehmer(N);
    ==> [1]:
    ==>    6442503168
    ==> [2]:
    ==>    [1]:
    ==>       [1]:
    ==>          2
    ==>       [2]:
    ==>          2
    ==>    [2]:
    ==>       [1]:
    ==>          3
    ==>       [2]:
    ==>          2
    ==>    [3]:
    ==>       [1]:
    ==>          2097169
    ==>       [2]:
    ==>          2
    list L=primList(1000);
    PocklingtonLehmer(N,L);
    ==> [1]:
    ==>    3221246976
    ==> [2]:
    ==>    [1]:
    ==>       [1]:
    ==>          2
    ==>       [2]:
    ==>          2
    ==>    [2]:
    ==>       [1]:
    ==>          3
    ==>       [2]:
    ==>          2
    ==>    [3]:
    ==>       [1]:
    ==>          1048583
    ==>       [2]:
    ==>          2

User manual for Singular version 4.4.1, 2025, generated by texi2html.