Encryption

What is Encryption?

In cryptography, encryption is a method that convert the plain text or data from readable to an encoded version, and usually the encryption requires an encryption key. To decode the encrypted data, user will need to acquire the same encryption key as the encoder to be able to view the decrypted message.

Why do we need encryption

Encryption is one of the most important way to provide security. We use the encryption every day in our life, for example: messages, emails and data transmission.

How does a basic encryption process work

1.Use an encryption algorithm/a key

2.Creates ciphertext

3.User obtain the decryption key and the encoded message

4.Decrypt the ciphertext using the key

There are two types of key, symmetric and asymmetric. Symmetric key is the key that can be used as both encryption and decryption key. Asymmetric key, aka public key cryptography, that contains a public key and a private key. Public key can be known by everyone, private must be private, and no one else should know the private key except for the sender and the receiver.

Benefits

Primary: Protect data from the network when it is transmitted

Authentication: the origin of a message can be verified.

Integrity: proof that the contents of a message have not been changed since it was sent.

Nonrepudiation: the sender of a message cannot deny sending the message.

Limitations

Hacker can use basic but “brutal force” to decrypt the message

Side-channel attacks

Find the weakness of the cipher

Company vs. Law Enforcement. Eg. FBI vs. Apple