> Many more try to invent new constructions on top of the primitives. That's where things go wrong, in practice. Things go wronger when non-cryptographers try

> Many more try to invent new constructions on top of the primitives. That's where things go wrong, in practice. Things go wronger when non-cryptographers try to invent their own primitives, and that's what the saying "don't invent your own crypto" was invented to warn against.