Introduction to 3DES

Overview of Encryption and Decryption

Encryption is a process of coding information which could either be a file or mail message into cipher text a form unreadable without a decoding key in order to prevent anyone except the intended recipient from reading that data. Decryption is the reverse process of converting encoded data to its original un-encoded form, plaintext. A key in cryptography is a long sequence of bits used by encryption / decryption algorithms. The following example to represents a hypothetical 40-bit key: 

10101001 10011110 00011100 01010101

Types of Encryption

 Depending on the type of encryption, information can be displayed as various numbers, letters, or symbols. Those who work in cryptography fields make it their job, to encrypt information or to break codes to receive encrypted information.

Manual Encryption

Manual encryption is a type that involves the use of encryption software. These are computer programs that encrypt various bits of information digitally. Manual encryption involves the user's participation completely. The files wants to encrypt are chosen, and then an encryption type is chosen from a list that the security system provides.

Transparent Encryption 

Transparent encryption is another type of computer software encryption. It can be downloaded onto a computer to encrypt everything automatically. One of the most important secure types of encryption available because it doesn't leave anything that might be forgotten when using manual encryption. Every executable application and file created in the computer has an encrypted copy that can withstand power surges and protects information in case a computer is stolen.

Symmetric Encryption

All encryption is done via a computer software program. You can easily encrypt information by yourself. One of the simplest ways to do this is through symmetric encryption. Here, a letter or number coincides with another letter or number in the encryption code. You can take any written text and substitute letters and numbers for their coded counterpart, thus encrypting the text.

Asymmetric Encryption

Asymmetric encryption is a secure and easy way that can be used to encrypt data that you will be receiving. It is generally done electronically. A public key is given out to whomever you want or posted somewhere for the public to see. They can encrypt information using the key and send it to you. This is often done when writing emails. This means encrypt the data with the public key, it can only be read again by whomever the private key has.

Types of Decryption

Symmetric Decryption

 In symmetric encryption, the same mathematical equation both encrypts and decrypts the data. The following example, a simple letter substitution cipher, such as A=B, B=C, etc., is symmetrical because you simply reverse the process to decrypt the message. If you send a message using a symmetric encryption method, the recipients must also have the key to decrypt the document.

Asymmetric Decryption

Asymmetric decryption methods, also known as public-key decryption, use a system involving a pair of linked keys. In this system, anything encoded with one key requires the other key to decrypt, and so on. When you encode a message using someone's public key, you know that only a recipient possessing the corresponding private key can read it.

Hashing 

Hashing is a form of encryption that uses a specialized one- way encryption key. If you hash a given volume of data, it will produce a unique output string to that data, but it is impossible to reconstruct the data from the output string. You can re-encode the original data and compare it to the result string to verify it. This can serve as a type of error correction in encoding. Hashing a message and providing that value to your correspondents ensures that they can hash the message themselves and compare the values. As long as the two output strings match, recipients know the message is complete and unaltered.