Quantum Encryption - A Means to Perfect Security?

In the past twenty years, the quantum properties of matter and light have been applied to the field of information security. Research has advanced to the point that actual devices using quantum properties are transmitting information over considerable distances. At this time, transmission speeds and hardware expense have generally limited the use of quantum devices to distribute keys rather than entire messages. There is controversy about how secure quantum messages are. It is possible to prove that the probability of message interception by an adversary is arbitrarily small, under ideal conditions. People and machines, however, can never be perfect, so there are many approaches to defeating quantum encryption. Some computer security experts have wondered why making the strongest link in a system even stronger will improve security overall. Since public key cryptography is so hard to decipher now, why spend so much time and money on an even more secure quantum encryption scheme? If deciphering is nearly impossible, why not use other techniques, such as social engineering, to eavesdrop? This paper will attempt to answer those questions.