The Migration

Hi everyone, I am writing this post to tell you that my blog isnotprime() has a new address! To continue to read me, go to

For those who have suscribe to the newsletter, this one will not work with the new address. I will add this option on but meanwhile, don’t hesitate to check the “new” blog.

See you on the other side…

Hello World!

No, I have not just created a new kernel… So hello everybody and welcome to my blog.

My name is Matthieu, I am currently a PhD student in cryptology at the Universit√© Clermont Auvergne (France). First of all, why isnotprime? This pseudonym is a nod to the function prime() of the computer algebra system PARI/GP which checks if a number n is prime or not; and since I am intrigued about prime numbers…

The purpose of this blog is to share with you, dear readers, some ideas, viewpoints or knacks about privacy, mathematics, free culture/software. There will certainly also be some posts on photography and LaTeX. This is not an exhaustive list, we will see.

Whatever, I hope you will enjoy it.