¿How Modern Cryptography Works?

I am going to document the entire learning and research process of the crypto world through this blog. I hope that if someone has the same curiosity about the subject, they can lean on my learnings.

There are five primary functions of cryptography:

Privacy/confidentiality: Ensuring that no one can read the message except the intended receiver.
Authentication: The process of proving one’s identity.
Integrity: Assuring the receiver that the received message has not been altered in any way from the original.
Non-repudiation: A mechanism to prove that the sender really sent this message.
Key exchange: The method by which crypto keys are shared between sender and receiver.

Encryption uses an algorithm to scramble, or encrypt, data and then uses a key for the receiving party to unscramble, or decrypt, the information. The message contained in an encrypted message is referred to as plaintext. In its encrypted, unreadable form it is referred to as ciphertext. Modern cryptography is based on three types of technology: symmetric cryptography, asymmetric cryptography and the hash…