A Web-only Primer on Public-key Encryption

Friday, 23 August 2002, 12:35 AM EST

A few terms first: cryptology, the study of codes and ciphers, is the union of cryptography (codemaking) and cryptanalysis (codebreaking). To cryptologists, codes and ciphers are not the same thing. Codes are lists of prearranged substitutes for letters, words, or phrases—i.e. "meet at the theater" for "fly to Chicago." Ciphers employ mathematical procedures called algorithms to transform messages into unreadable jumbles. Most cryptographic algorithms use keys, which are mathematical values that plug into the algorithm. If the algorithm says to encipher a message by replacing each letter with its numerical equivalent (A = 1, B = 2, and so on) and then multiplying the results by some number X, X represents the key to the algorithm. If the key is 5, "attack," for example, turns into "5 100 100 5 15 55." With a key of 6, it becomes "6 120 120 6 18 66." (Nobody would actually use this cipher, though; all the resulting numbers are divisible by the key, which gives it away.) Cipher algorithms and cipher keys are like door locks and door keys. All the locks from a given company may work in the same way, but all the keys will be different.

[ Read more ]




Spotlight

eBook: Cybersecurity for Dummies

Posted on 16 December 2014.  |  APTs have changed the world of enterprise security and how networks and organizations are attacked. These threats, and the cybercriminals behind them, are experts at remaining hidden from traditional security while exhibiting an intelligence, resiliency, and patience that has never been seen before.


Weekly newsletter

Reading our newsletter every Monday will keep you up-to-date with security news.
  



Daily digest

Receive a daily digest of the latest security news.
  
DON'T
MISS

Wed, Dec 17th
    COPYRIGHT 1998-2014 BY HELP NET SECURITY.   // READ OUR PRIVACY POLICY // ABOUT US // ADVERTISE //