We are pleased to announce the release of GMP-ECM 5.0.3. The source file is available from:
This is a fix release for bugs in versions 5.0, 5.0.1 and 5.0.2. The main changes with respect to version 5.0.2 is the following: versions 5.0, 5.0.1 and 5.0.2 have a nasty bug that prevents them from finding some factors. The proportion of missed factors is conjectured to be about 3% on 32-bit machines, and 1.5% on 64-bit machines.
To check if the bug occurs with your version, type:
$ echo 3213162276640339413566047915418064969550383692549981333701 | ecm -sigma 2735675386 3897500If you don't get an output as follows, your version is buggy.
GMP-ECM 5.0.3 [powered by GMP 4.1.2] [ECM] Input number is 3213162276640339413566047915418064969550383692549981333701 (58 digits) Using B1=3897500, B2=5831973006, polynomial Dickson(12), sigma=2735675386 Step 1 took 21930ms Step 2 took 27810ms ********** Factor found in step 2: 3213162276640339413566047915418064969550383692549981333701 Found input number NAlternatively a patch wrt ecm-5.0.1 enables you to check if the bug occurs. Compile ecm-5.0.1 with that patch and run it on your input number. An error will be reported if the bug occurs. Note however that the bug does not systematically happen for a given input number, even for fixed B1 and B2 bounds.