Cryptography: the importance of not being different

Cryptography is difficult. It combines mathematics, computer science, sometimes electrical engineering, and a twisted mindset that can figure out how to get around rules, break systems, and subvert the designers' intentions. Even very smart, knowledgeable, experienced people invent bad cryptography. In cryptography, there is security in following the crowd. A homegrown algorithm can't possibly be subjected to the hundreds of thousands of hours of cryptanalysis that DES and RSA have seen. A company, or even an industry association, can't begin to mobilize the resources that have been brought to bear against the Kerberos authentication protocol, for example. No one can duplicate the confidence that PGP offers, after years of people going over the code, line by line, looking for implementation flaws. By following the crowd you can leverage the cryptanalytic expertise of the worldwide community, not just a few weeks of some analyst's time.