Encryption

1. Encryption

2. Definition
• “Encryption is the process of encoding a message or
information in such a way that only authorized parties can
access it and those who are not authorized cannot.”

3. Encryption and Decryption
• Encryption is the process of using an algorithm to transform information
to make it unreadable for unauthorized users. Once the information is
encoded, it requires decryption to be understood.
• Decryption is the process of transforming data that has been rendered
unreadable through encryption back to its unencrypted form.
• The encoded data reverts back to its original form, whether it contains
texts or images, so that it makes sense to the human reader and/or the
computer system. This process may be automated or be conducted
manually.

4. Symmetric key encryption
• Symmetric key encryption is based on algorithms that apply the same keys for both encryption
and decryption. It’s the same concept that worked for the Scytale in which the same size
cylinder is used both to set the code and to rewrap the strips to make sense of the apparently
random letters.
• The same key that rendered the plaintext into ciphertext will turn the ciphertext back into
plaintext In his blog, Panayotis Vryonis offers the analogy of locking something away in a box.
The same key used to remove the contents from view is used to unlock the box and reveal
them.

5. Asymmetric Key Encryption
• This is also sometimes called public key encryption. The name is a bit misleading
because the asymmetry actually depends on having both a public and a private key.
The public key is used to encrypt the message that is decrypted with the private key.
• You can also encrypt data with the private key and have the receiver decrypted with
the public key. The point is just that different keys are used for two functions.

6. Example

7. Why is encryption important?