Concluding Remarks

Cryptography provides solutions to the problem of secure communication in WWW;
SSL is a (relatively) secure protocol that is currently used for HTTP and will be used for other services too (NNTP, FTP, TELNET);
Cryptography is controversial because:

theoretically, it is not possible to prove correctness; there is suspicion around cryptographic algorithms;
patents and licensing procedures do not allow spread of commercial application;
the legal status of cryptographic products (considered munitions) obstructs the spread of the application with cryptography on the international market and also creates ambiguous situations for the people involved in this area (see for example PGP - P. Zimmerman or Identification Schemes - Adi Shamir);