There are three widely held beliefs about cryptology which underpin much research on the subject, guide substantial industrial investment and inform most of the associated public policy debate. These are, first, that the cryptographic systems are mostly used to keep communications secure, in the sense of ensuring that an electronic message is secret and/or authentic. In the second of these roles, cryptology provides a useful (if not only) means of securing electronic evidence in such a way that it will be accepted by a court, and is thus indispensable to the future development of electronic commerce. Third, most attacks on cryptographic systems involve technical skill at cryptanalysis, and such systems can therefore be made sufficiently robust by using standard, well studied encryption and signature algorithms. Shows that these three beliefs are almost completely mistaken.