"The point of academic attacks is not exhibiting practical breaks; the point is that only a trained cryptographer can tell whether a given algorithm is secure or not. The author of an algorithm says: "My cipher is secure, and trust me, I am an expert at this. And to prove that I am a real good expert, I challenge other experts to find even the most impractical, academic flaw in my cipher"."
January 1, 1970
https://en.wikiquote.org/wiki/Cryptography