Ciphers, Keys & Encryption Algorithms

Few things in the world of bits-n-bytes seem more alluring & intriguing than encryption algorithms .. with colorful names such as Blowfish (named after a deadly delicacy), Serpent (which took down mankind) & Rijndael (pronounced 'rain-dahl') .. conjuring up images of clandestine transactions being conducted by rogue spies and covert agents.

There I was, minding my own business, learning computer programming by watching the CS-50 course (at Harvard), when Malan mentioned ROT13. Say what? So I asked the Google.

Julius CaesarA slippery slope it was. First I learned about the Caesar cipher, which Julius used in ancient Rome to communicate with his generals waging campaigns out in the field. (Cool, yet hardly seems secure.)

But what about us? What ciphers should we be using today to protect our valuable data & sensitive files?

The best program (most seem to agree) for encrypting your own files & drives is » TrueCrypt. (Now at v6.3a.) TrueCrypt is both free & open source, and it's list of features is (truly) impressive.

If you feel compelled to pay either $60 or $100 for a similar program, the best option(s) seem to be » BestCrypt and/or Volume Encryptor.

I downloaded a copy of both programs and took each for a test-drive around the digital block. Most surprising was how little CPU resources these programs use .. to encrypt (and decrypt) files on-the-fly. We're talking negligible .. even with my battered 5-year old laptop ( .. that's missing an i-key).

These programs work by creating a file on your hard drive (however big you want) that looks (and is used) like a typical/standard logical drive, which you can use to both store and retrieve files as needed. [ I made each of mine 2-gigs. ]

They can also encrypt an entire logical drive, including your system/boot drive (where Windows resides).

An algorithm is simply a sophisticated mathematical formula for scrambling the bits associated with the files on your hard drive (.. so nobody can read them). The hard part, it would seem, would be the subsequent reassembly.

The next question you might have is » What's considered the 'best' encryption algorithm? .. seeing the program will ask which one you want to use. The word 'best,' as you know, can mean different things to different people (who have different priorities).

People intimately familiar with encryption algorithms have declared (drum roll, please) » Rijndael = 'best.' It's the current Advanced Encryption Standard (AES). Note that AES is NOT an algorithm, per se, tho the term is often used that way (.. as a synonym for the Rijndael algorithm). Rather it's a standard. Rijndael is the actual algorithm used in/by/with the AES standard.

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Rijndael was published in 1998 by two Belgians (Vincent Rijmen and Joan Daemen). The decision however, to select Rijndael as the current/new AES was not unanimous. Serpent (published 1998) garnered 59 votes to Rijndael's 86 and came in second. Twofish (which replaced Blowfish in 1998) came in third with 31 votes.

Serpent was one of the AES finalists. It was not selected as the proposed AES algorithm even though it appeared to have a higher security margin than the winning Rijndael. In spite of this, Rijndael was selected as the AES for its combination of security, performance, efficiency, implementability, and flexibility.

NSAEncryption algorithms seem to be divided into two main categories » private-key and public-key (.. also referred to as Symmetric & Asymmetric encryption).

Prior to 1976, all encryption applications were private key. That's when RSA was introduced as the first public-key algorithm. RSA stands for Rivest, Shamir & Adleman, and is named for/after the MIT cryptographers who invented it.

PGP is another name you hear mentioned in these circles. PGP has some freeware versions available, but they haven't been updated for years.

The best way to draw attention to yourself, I'd assume, would be to start sending encrypted emails around the 'Net (.. with the subject heading » 'Jihad!'). Speaking of secure email .. I heard Hushmail was/is the best. (It's what most mistresses of high-profile politicans prefer to use, I'm told.)

One last thing. Seems it's possible to use multiple algorithms together (for example » Rijndael + Twofish + Serpent) in what is termed a 'Cascade' .. which would seem MORE secure, right? Some however, claim the practice of combining algorithms is actually LESS secure, because it introduces more vulnerabilities.

Decode the following cipher to earn your Rad Crypto badge » V pnzr. V fnj. V rapelcgrq. [Hint.]

For more along these lines, here's a Google search preconfigured for the query » encryption algorithm key cipher

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This page contains a single entry by Rad published on February 23, 2010 2:23 AM.

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