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.

Executable for Linux 64-bit (Ubuntu 12.04/x86-64 architecture)
Compiled with Free Pascal 2.6.2 and Lazarus 1.0.12
Primo for Linux screenshot

A short description of the ECPP algorithm can be found at Elliptic Curve Primality Proving by Eric Weisstein (from MathWorld — A Wolfram Web Resource).

  • What does "LX64" stand for?
    Linux 64-bit.
  • Does it exist a Primo version for an other operating system than Linux?
    No, there is not.
  • Is the LX64 version for multicore processors?
    Yes, it is.
  • Does the LX64 version run with Linux distributions other than Ubuntu 12.04?
    It should do (but I do not know).
  • Does it exist a command line version?
    No, not yet.

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

NSieve parametersTasksRunning time
10999 + 72000 dd23 bits851.44s
101999 + 73212000 dd23 bits813mn 57s
102999 + 18873000 dd24 bits81h 11mn
103999 + 47714000 dd25 bits8     3h 48mn [1]
104999 + 226695000 dd26 bits89h 17mn

[1] This number is the third ECPP record set with Primo. Its certification, thirteen years ago, took 2856h!

v4.1.0 (January 4, 2014)
  • Fixed a bug concerning the verifier code. The new Primo versions can produce tests of type 3 or 4 with a S value equal to 1 but the verifier code was not updated accordingly. Thanks to Dana Jacobsen who reported it.
  • Fixed a cosmetic bug.
  • Modified the input file format and the expression parser. See "Input file" in the help file.
  • Modified (slightly) the backtrack rules.
  • Added new discriminants.
  • Added an extended sieve stuff.
  • Replaced the tkcs, tkc1, tkc2 and tkcv executable files with ptk0, ptk1, ptk2 and ptk3.
 Previous changes


The software Primo may be used free of charge but you should read the End-User License Agreement before downloading and using it.

Though it is possible, it is not advised to resume with this new version a certification started with a previous version.

  primo-410-lx64.7z    16.1 MB   Executables  (binary files)

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