Sunday, September 25, 2011

Basics of encryption -Part 01

Encryption ? What is it? What’s its relevance to you? Do you think you have never used any kind of an encryption method? If your answer is “no”, definitely you are mistaken!. We use encryption in many events of our day-to-day life. Specially as Internet users encryption helps us a great deal. We are just ignorant about its services. As an example, when you login to your mail account/facebook account you are receiving the protection of encryption methods. We benefit from encryption even in our day-to-day activities like using the ATM. Without the use of encryption technologies, use of ATM machines would have been far more riskier. Through this series of articles, I’m going to give you an introduction to encryption and a basic introduction to some encryption categorizations.
First of all, let’s get familiarized with the terminology.

This is the study of creating messages in a form of secret code that masks the actual message and displays something completely different. Usually complex mathematical algorithms and computers are used to do this. This encrypted message will mean nothing to a casual observer, but the intended receiver can reconstruct the original message using a certain predefined methodology.
A data set prior to the encrypting it is called “plaintext”.
Encryption is the implementation of cryptography. Data is converted to an encrypted format using encryption. This encrypted data could be password protected. To decrypt( that means to retrieve the original data) the receiver should have the proper key and/or password.
Plaintext data is called “ciphertext” once it is encrypted.
An algorithm is a precise set of instructions that can be followed to get a reasonable output to a problem. As an example, when sound doesn’t come from your computer speakers, you first check the volume controller of the computer, then you check whether the speaker system has got the power correctly, then you check the volume controller of the speaker system, then you check the connection between the computer and the speaker system. This is more like an “if-then” procedure.
It’s an algorithm that contains precise instructions on how to encrypt and decrypt data. There are two main types of cyphers. The first one rearranges the characters in a file. As an example, the word “ishan” could be rearranged as “snahi”. The second method completely changes the content and replaces it with predeifned characters. As an example, the word “ishan” can be encrypted as “abcde” where i=a, s=b, h=c, a=d, n=e .
If a process seems to be random, but if it is not random, then thats called pseudorandomness. If a series of things( lets say numbers) seems to be random, but if they are not random, the it’s called a pseudo random series.
It’s a collection of random or pseudorandom characters that is combined with a plaintext message to produce an encrypted message (the ciphertext).
This is a parameter which determines the functional output of a cryptographic algorithm or cipher. A key is essential to get a result that is useful.
Brute force attack:
When a person tries to crack the encryption algorithm by using an intensive trial-and-error key/password reproduction procedure, it is called a brute force attack.
I think this is enough for a single post. Hope to you see you soon with the next part of this article…!

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