ByteSizeNotes Chapter 2.3
Chapter 2.3

Encryption

Plain Text & Ciphertext

  • Plain text:original data sent (no encoding)
  • Ciphertext:plaintext that has been encoded

State the purpose of encrypting data

  • Data becomes scrambled/unreadable.
  • If intercepted it will not be understood

Symmetric Encryption

  • Data is encrypted and decrypted using the same key/algorithm
  • Encryption algorithm is used
  • Data before encryption is known as plain text
  • Data after encryption is known as cipher text
  • Key is sent to receiver (to allow data to be decrypted)

Explain how data is encrypted using symmetric encryption

  • Data is encrypted and decrypted using the same key
  • Plain text is encrypted into cipher text
  • Data is encrypted using an algorithm... that uses a key
  • The key can be generated using an algorithm
  • The key is transmitted to the receiver

Asymmetric Encryption

  • Asymmetric encryption was developed to overcome the security problems associated with symmetric encryption
  • Uses a public key and a private key
  • Public key is available to everyone
  • Private key only known by the computer user
  • Both keys are needed to encrypt and decrypt data

State differences and similarities between Symmetric and Asymmetric

Differences

  • Symmetric has a shared key... to encrypt and decrypt
  • Both the sender and receiver know the key
  • Asymmetric has different keys (public + private) public to encrypt the data and private to decrypt anyone can know the public key but only those intended know the private key

Similarities

  • They both use a key
  • They both scramble data
  • They both turn plain text to cipher text

SSL (Secure Sockets Layer)

State how SSL secures the data for transmission

  • It encrypts it
  • Uses digital certificates

**The data for the web page is transmitted using SSL --- Fill in the

blanks:**

  • The web browser asks the web server to identify itself. The web server sends back its digital certificate. The web browser authenticates the digital certificate.
  • If it is authentic,encrypted data transmission begins.