hurrengoa
Cryptographye: art and science    The objective of cryptography is to render texts, sounds, images and whatever other type of information code used indecipherable to those who aren't meant to understand it. In order to achieve this, the original information is transformed and only the sender and receiver can read the changes. Nowadays, codes are mostly used in computing, mostly to protect information in computers and on the net and to confirm digital signatures. It's like if you send a letter without an envelope; the postman will be able to read what has been written. The same thing happens to messages sent over the net; they can be picked up if they are not protected. To avoid this risk, complex mathematical functions are used to encode and hide the messages.
Cryptography is an awful lot older than computing all the same. The hieroglyphics used by ancient Egyptian priests is an example of this. However, it's in times of war that codes have been most used. Cryptography comes from the Greek words Kryptos which means "hidden" and graphein which means "written". In the Greek city of Sparta the military were using the scytale system about 400 BC. The scytale was a tapered baton around which was wrapped a spiral strip of parchment containing the message. Words were then written lengthwise along the baton. Unless a baton of the same shape was used to read the original, the message couldn't be understood.
The system implanted by Julius Caesar was much simpler: each letter was replaced by the corresponding one three letters down. A few centuries later on, Middle-Aged copyists started writing without vowels and they would replace them with dots or any consonant. At other times they would use the alphabet of the zodiac.
The use of codes came on leaps and bounds with all the dirty tricks going on around the popes. So much so that it was a servant of Clemence VII who wrote the first handbook on cryptography. In 1466, Leon Battista Alberti came up with a system that used more than one alphabet; every three or four words it changed alphabets. The sender and the receiver had to agree on the position to set two concentric circular scales of letters. According to their choice, the words would mean one thing or another. There was a revolution in codes during the XX Century. The rotor teletype disk system, based on Alberti's design, was first to come along. The first patent is from 1919. Then Arthur Scherbius invented the Enigma machine. This ciphering machine, whose codes were claimed unbreakable, was actually what caused the Nazis to lose WWII when Englishman Alan Turing invented machines called "Bombe", able to crack the codes.
After WWII, new electronic and digital technology was applied to cryptography. It has become more complex than ever and quantum physics offers even more possibilities. But as Edgar Allen Poe put it: "It's difficult for someone to create a code that another can't crack".
(By: elhuyar)

Moby Dick, the white whale´s black predictions
Herman Melville's "Moby Dick" is undoubtedly one of the most praiseworthy books on the relationship between humans and the sea. That's what it seems like on the surface anyway. If you delve beneath the surface of the book, you'll find another reading that deals with the neverending fight between mankind and its destiny. Fair enough, but there are even deeper lightless places to be found in Moby Dick, originally called The Whale. The book hides a much darker story in its letters and words and it has been ignored by the majority of readers of the story. Herman Melville published the first version of the book in 1851. Bartleby's father, later present in his writings, is nowhere to be found. The murder of many modern-day leaders is encrypted into Moby Dick. You can find factual detailed explanations of different murders on different pages. Is it a coincidence? Some paranoia from a Moby Dick freak? The imagination of a reader with too much time on their hands? ...Yep, probably a bit of one and all, but there's a great buzz to be got out of fooling around with serendipity...
(By: the balde)