These types of encryption algorithms are called symmetric because they use the same key to encrypt and decrypt messages.
An encryption mechanism that replaces parts of your plaintext with ciphertext
ex. caesar cipher
shifts letters in a message to make it unreadable if intercepted.
Takes a stream of input and encrypts the stream one character or one digit at a time, outputting one encrypted character or digit at a time.
stream cipher has a 1 to 1 relationship with input and output data.
The cipher takes data in, places it into a bucket or block of data that’s a fixed size, then encodes that entire block as one unit.
If the inputted data isn’t big enough to be ciphered, padding will be added for plain text to fit into blocks evenly.
To avoid key reuse, initialization vector (IV) is used some random data integrated into the algorithm.
In order for the encryptped message to be decoded, the IV must be sent in plain text along with the encrypted message. A good example of this can be seen when inspecting the 802.11 frame of a web encrypted wireless packet. The IV is included in plain text right before the encrypted data payload.