Auguste Kerckhoff is best known for a series of two essay she published in 1883 in the Journal of Military Science. These articles surveyed the state of the art in military cryptography and included many pieces of advice and rules of thumb, including his famous six principals of practical cipher design. The most well known is the second of his six principals, otherwise known as Kerckhoff's Law. This law states that "There is no secrecy in the algorithm - It is all in the key.".