Thank you to Adrien-Marie Legendre and Carl Gustav Jacob Jacobi for their symbols
In science, it is difficult to avoid Adrien-Marie Legendre, as there are so many things named after him: Fourier–Legendre series; Gauss–Legendre algorithm; Legendre chi function; Legendre duplication formula; Legendre–Papoulis filter; Legendre form; Legendre polynomials; Legendre sieve; Legendre symbol; Legendre transformation; Legendre wavelet; Legendre–Clebsch condition; Legendre–Fenchel transformation; Legendre’s constant; Legendrian knot; and Gamma function–Legendre formula.
And, so, where does Legedre help with your online security? Well, you will find his method used in elliptic curve methods, which are used to protect your online identity, and the security of the communications that you have with this Web page. So, let’s look at the Legendre Symbol.
Quadratic residues
Okay. Let’s say you want to determine the square root of 16. Well, that’s easy … as the answer is 4. But now, what is the square root of this:
6131408466595397710012614540363234062359700887928125190599453844504986420213585686778819217466610878266563405415556
Ans: 2476168101441297080746512578325117519920374855425678540834L