In computational number theory, Cipolla's algorithm is a technique for solving a congruence of the form x 2 ≡ n, {\displaystyle x^{2}\equiv n{\pmod {p}},} where x, n ∈ F p {\displaystyle x,n\in \mathbf {F} _{p}}, so n is the square of x, and where p {\displaystyle p} is an odd prime. Wikipedia