  Many reports regarding online fraud in varieties media create skepticism for
conducting transactions online, especially through an open network such as the
Internet, which offers no security whatsoever. Therefore, encryption technology
is vitally important to support secure e-commerce on the Internet. Two
well-known encryption representing symmetric and asymmetric cryptosystems as
well as their applications are discussed in this paper. Encryption is a key
technology to secure electronic transactions. However, there are several
challenges such as crytoanalysis or code breaker as well as US export
restrictions on encryption. The future threat is the development of quantum
computers, which makes the existing encryption technology cripple.
