What is Encryption ?

Encryption is the process used to store data in encrypted form. This process was used from ancient time, in past, most of the people were used encrypted language to communicate with another people. The main reason for using encryption is, no one in this world wants that his information leak without his permission. 

Encryption From Ancient Time

Ancient time Kings also created the secret encrypted language map to hide their wealth from people. One of the best examples was "Voynich Manuscript" Latin script was written in the 15th century. No one person from this world wasn't able to decode this script because there no any key left for decodetion.

Voynich Manuscript

Computer encryption is likely little-bit same. In today computer network environment we are using two major methods for data encryption.

Computer Encryption

1. Symmetric Encryption: In this encryption, there is only one key used to decrypt the data. When you locked data with this cryptosystem and want to send another person, the person on the other end needs secret (key) to unlock the data. The Same key required for unlocking the data. 

Symmetric Encryption Source IBM.

  • Symmetric key encryption doesn't require as many CPU (Central Processing Unit) cycles as asymmetric key encryption, so you can say it's generally faster. 
  • When you transfer data to other people if by mistake hackers intercept data half of its path since there is no key transmitted with the data, the chances of data being decrypted are null.
  • A symmetric encryption use password authentication to prove the receiver’s identity.
  • In symmetric encryption only secret key decrypt data. 
  • The first disadvantage of this encryption sender has to share private key with the receiver. If the receiver doesn't have private key he doesn't even decrypt data. 
  • If hackers intercept sender private key from his system, they can easily decode that information. 
  • Cannot provide digital signatures that cannot be repudiated.

2. Asymmetric Encryption: This encryption slightly different from Symmetric. In asymmetric encryption, two different key will be used for encryption and decryption. For eg. when you send a mail to your friend on Gmail, the private key is required for encrypting text and if your friend wants to read that text public key is necessary for him to read your message.

Asymmetric Encryption

In this case, sender and receiver don't have to share private or public key with each other. All conversation is automatic between both systems. There are no any few chances left for an attacker to decode your conversation.This is a type of mathematical algorithm. Asymmetric Encryption is also known as Public Key Cryptography, since users typically create a matching key pair, and make one public while keeping the other secret.

  • The main advantage is of this encryption, there is no need for exchanging keys, thus eliminating the key distribution problem.
  • The primary advantage of public-key cryptography is increased security the private keys do not ever need to be transmitted or revealed to anyone.
  • It can provide digital signatures for authentication and non-repudiation. 

  • The main disadvantage of using public-key cryptography for encryption is speed. It's a type of algorithm and process is automatic so it requires time to encrypt and decrypt the data. 

These are two major encryption are using today time.  In next topic, we will discuss Encryption standards, which software are used for both symmetric and asymmetric encryption and encryption protocols.