A little knowledge is a dangerous thing
Bruce Schneier demonstrates the truth of the old saying in a must-read blog entry.
In a nutshell, Nature published an article written by a physicist with little or no background in cryptography, claiming to have devised a mechanism foroptically transmitting encrypted messages using a “chaotic carrier”. Bruce trains his skeptical and expert eye on the article and demolishes it: he shows how the system allows anyone with a compatible receiver to decrypt traffic, that the system offers no ability to change keys, and more. The result is an object lesson on the value of peer review (even if it is not anonymous and is informal), and of the dangers of not doing a literature review.