Intro to Encryption

An anonymous reader submitted a Techworld story which is a sort of encryption primer. The difference between codes & cyphers, and what all those acronyms like RSA and DES actually mean. This is good primer material for newbs, and a good refresher for fogeys.

Comments

Inaccuracy in article?

[DarkHelmet]

About RSA: Current hardware means key lengths should be 1024 bits for complete security. The present generation of web browsers use 128-bit keys so cannot be considered secure against a determined and sufficiently well-resourced attack.

Certificates are 1024 or 2048 bit with SSL. On the other hand, once the key is sent and shared, a 128 bit symmetric form of encryption is used. The only thing RSA is used for is sending / receiving the symmetric encryption key, yes?

Correct me if I'm wrong.

Much better than that article

[yahyamf]

I would strongly recommend the Code Book by Simon Singh over that short article. It takes the reader from the Ceaser cipher all the way to quantum codes and is a very enjoyable read. The Codebreakers by David Kahn is also an excellent though somewhat lengthier volume

Difference betwen Codes and Cyphers?

[NardofDoom]

That's easy. Code is what I stare at all day, while Cypher is the jerk who betrayed Neo in The Matrix. Duh.

Handbook

[Ann Coulter]

The Handbook of Applied Cryptography: http://www.cacr.math.uwaterloo.ca/hac/ is a very detailed guide to some cryptographic algorithms and theories. This is not for newbies at all. For those wanting to implement a particular cipher, this book is the place to refer to. On top of everything, it is free.

Re:intro to encryption

[Anonymous Coward]

a b c d e f g h i j k l m n o p q r s t u v w x y z
n o p q r s t u v w x y z a b c d e f g h i j k l m

first post!

Safe encryption

[darkstream]

When I want to email with a new friend using PGP encryption, I send him my key one character at a time via snail mail using newspaper clippings. The only time this becomes a problem is when the post office laps itself and delivers more than one letter a day, or gets an earlier letter there later than a later letter, but it's the only way to be sure the key never falls into enemy hands. Of course, I don't get to email many people these days...

Applied Cryptography

[Meostro]

Bruce Schneier's Applied Cryptography is another excellent resource for all you crypto-geeks out there. It goes from the basics (including the substitution cipher presented in the article) through basic crypto (ENIGMA, DES) all the way up through state-of-the-art (don't think AES was in my 1st ed., but I believe it's in there now). He talks about everything from the theoretical to the practical, hash collisions to rubber-hose cryptography.

It comes with source too! You know you love source....

Re:I realized something while reading the article.

[grahamsz]

Say tommorrow someone discovered an efficient technique for computing the prime factors of a composite. That would blow RSA and probably DSA out of the water - rendering most parts of PGP/GPG worthless.

Unless we have other asymetric ciphers to fall back on, then e-commerce would be wiped out.

Additionally algorithms with very low computational requirements are of particular importance since we need encryption that can run on smart cards, but cant be broken by super computers.