Techniques for Encryption and Decryption


Encryption is a technique for transforming information on a computer in such a way that it becomes unreadable for unauthorised person.

if someone is able to gain access to a computer with personal data on it, they likely won’t be able to do anything with the data unless they have complicated, expensive software or the original data key.

Three different encryption methods:

  • Hashing
    Hashing creates a unique, fixed-length signature for a message or data set. Each “hash” is unique to a specific message, so minor changes to that message would be easy to track. Once data is encrypted using hashing, it cannot be reversed or deciphered. Hashing, then, though not technically an encryption method as such, is still useful for proving data hasn’t been tampered with.
  • Symmetric methods 
    Symmetric encryption is also known as private-key cryptography, and is called so because the key used to encrypt and decrypt the message must remain secure, because anyone with access to it can decrypt the data. Using this method, a sender encrypts the data with one key, sends the data (the ciphertext) and then the receiver uses the key to decrypt the data.
  • Asymmetric methods
    Asymmetric encryption, or public-key cryptography, is different than the previous method because it uses two keys for encryption or decryption (it has the potential to be more secure as such). With this method, a public key is freely available to everyone and is used to encrypt messages, and a different, private key is used by the recipient to decrypt messages.


key terms used:

Data that can be read and understood without any special measures is called plaintext or cleartext.

The method of disguising plaintext in such a way as to hide its substance is called encryption.

Encrypting plaintext results in unreadable gibberish called ciphertext.

You use encryption to ensure that information is hidden from anyone for whom it is not intended, even those who can see the encrypted data. The process of reverting cipher text to its original plaintext is called decryption.


How Encryption works:

Encryption is an interesting piece of technology that works by scrambling data so it is unreadable by unknown person or hackers.

for example:


These are the jumbled words but i want to send message “hi is the best site for ugc net”


Techniques for encryption:

‐ DES (Data Encryption Standard) is a symmetric cipher defined in Federal Information Processing (FIPS) Standard Number 46 in 1977 as the federal government approved encryption algorithm for sensitive but non‐ classified information. DES was developed by IBM and was based upon IBM’s earlier Lucifer cipher. DES utilizes a 56‐bit key. This key size is vulnerable to a brute force attack using current technology.

‐ Triple DES is a variant of DES, Triple DES, provides significantly enhanced security by executing the core DES algorithm three times in a row. The effect of making the DES encryption much more difficult to brute force. Triple‐DES is estimated to be 2 to the 56th times more difficult to break than DES. Triple DES can still be considered a secure encryption algorithm. Triple DES is also written as 3‐DES or 3DES.

‐ AES (Advanced Encryption Standard) is a symmetric cipher defined in Federal Information Processing (FIPS) Standard Number 197 in 2001 as the federal government approved encryption algorithm. The NSA has approved 128‐bit AES for use up to SECRET level and 192‐bit AES for use up to TOP SECRET level. AES is based upon the Rijndael algorithm, which was invented by Joan Daemen and Vincent Rijmen. AES specifies three approved key lengths: 128‐bits, 192‐bits and 256‐bits.

-RSA is a public-key encryption algorithm and the standard for encrypting data sent over the internet. It also happens to be one of the methods used in our PGP and GPG programs.

Unlike Triple DES, RSA is considered an asymmetric algorithm due to its use of a pair of keys. You’ve got your public key, which is what we use to encrypt our message, and a private key to decrypt it. The result of RSA encryption is a huge batch of jumbo that takes attackers quite a bit of time and processing power to break.

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