Encryption

• Primarily used to protect data in case it has been hacked/accessed illegally
• Data being transmitted over Internet is vulnerable to hackers
• Encryption will not prevent hacking but it makes the data incomprehensible unless the recipient has the necessary decryption tools
• Plaintext


  the original message to be encrypted
• Ciphertext


  the encrypted message
• Encryption


  the process of converting plaintext into ciphertext
• Key


  a sequence of letter, numbers and other characters used to encrypt or decrypt
• Encryption Algorithm


  the method for encrypting the plaintext
• Symmetric encryption


  • uses a secret key which can be a combination of letters, numbers and other characters
  • a single key is used to encrypt and decrypt a message and must be given to the recipient of your message so that they can decrypt and read it
• Example of symmetric encryption

  Caesar shift cipher
• Caesar shift cipher


  each letter is replaced by a letter 'n' number of positions further on in the alphabet

  'n' can be any number but it will remain the same for one message
• Asymmetric encryption


  • number of risks if encryption key falls into wrong hands
  • more secure method to use it public key encryption or asymmetric encryption
• Public Key Encryption


  • private key and public key needed
  • User A receives public key and a private key from a certificate authority
  • User B uses public key sent to them by User A to send n encrypted message
  • User A then decrypts the message using their private key which is not shared with anyone else