Primo is a primality proving program based on the ECPP (Elliptic Curve Primality Proving) algorithm. Given positive odd integers, it tests whether these integers are prime, and if they are it produces primality certificates. With Primo, one can check crypto-primes and prove whether they are actually prime... or not.

The following certification running times were obtained with Primo using an Intel i7-2600 3.4GHz processor.

[1] This number is the third

ECPP record set with Primo. Its
certification, thirteen years ago, took 2856h!

The software Primo may be used free of charge but it might be a good idea to read the
End-User License Agreement before downloading and using it.