Sender encrypt the information using an encryption algorithm with a encryption key. This produces the encrypted message which is unreadable, generally called cipher-text. When the legitimate receivers receive the message they use a decryption algorithm with a secret decryption key to decrypt the message and extract the original information.
- Sender prepare the message.
- Encrypt the message using encryption key
- Encrypted message is sent to the receiver (message is in unreadable form no one can extract the information directly.)
- Receiver receive the message and decrypt the message using decryption key
- Original message is produced by the receiver
Assumption: Though the encrypted information is hacked by an adversaries they don't have the secret description key to decrypt the message. So the information is safe.
There are two types of encryption mechanisms
- Symmetric Encryption - A single key is used for both encryption and decryption. The key is shared among the senders and receivers. The requirement to have access to the key by both parties is one of the drawbacks of this mechanism.
- Asymmetric Encryption (Public Key Encryption) - Two separate keys are used for encryption and decryption. One key is made public and published, this is used to encrypt the message. The other key is kept private (secret) and used to decrypt the message.