No. They don't. A whole group of people get together and the end result is good crypto or safe medicine. Sure, one person might have the idea. By the time it's

No. They don't. A whole group of people get together and the end result is good crypto or safe medicine. Sure, one person might have the idea. By the time it's included in, e.g. a Java Crypto library or OpenSSL, or your arm, it's been thoroughly reviewed by tens or hundreds of people. For example, "RSA" is the initials of the three people who invented it, by trying for some time to implement an idea published by two others two years earlier. Only a fool would say, "Bah, I know what I'm doing! Ship it!"