How Cryptography Works?

■ Plaintext: This is the original intelligible message or data that is fed into the algorithm as input.

■ Encryption algorithm: The encryption algorithm performs various substitutions and transformations on the plaintext.

■ Secret key: The secret key is also input to the encryption algorithm. The key is a value independent of the plaintext and of the algorithm. The algorithm will produce a different output depending on the specific key being used at the time. The exact substitutions and transformations performed by the algorithm depend on the key.

■ Ciphertext: Ciphertext is the scrambled message produced as output. It depends on the plaintext and the secret key. For a given message, two different keys will produce two different ciphertexts. The ciphertext is an apparently random stream of data and, as it stands, is unintelligible.

■ Decryption algorithm: This is essentially the encryption algorithm run in reverse. It takes the ciphertext and the secret key and produces the original plaintext.

For Example:- Let’s say you want to send a secret message to your friend. You could write the message on a piece of paper and seal it in an envelope. However, if someone intercepted the envelope, they could open it and read the message. Instead, you could encrypt the message using a cryptographic algorithm. This would transform the message into ciphertext that is unreadable by unauthorized individuals. 

You could then send the ciphertext to your friend, who could decrypt it using the same cryptographic algorithm and key. The security of a cryptographic system depends on the strength of the cryptographic algorithm and the secrecy of the keys. If the cryptographic algorithm is weak, then it may be possible to break the encryption and read the plaintext. If the keys are not kept secret, then they may be compromised, which would allow unauthorized individuals to decrypt the ciphertext.

Cryptography is a technique of securing communication by converting plain text into unintelligible ciphertext. It involves various algorithms and protocols to ensure data confidentiality, integrity, authentication, and non-repudiation. The two primary types of cryptography are symmetric key cryptography and asymmetric key cryptography and It plays a vital role in ensuring the security and privacy of information in today’s digital world and enables secure online transactions, protects sensitive data stored in databases, and ensures the confidentiality of communication. As technology continues to advance, cryptography remains a crucial tool in the ongoing battle to keep our information safe from hackers.

In this Cryptography Tutorial, we’ve covered basics and advanced concepts of Cryptography including symmetric-key cryptography, asymmetric-key cryptography as well as Cryptanalysis, Public Key Cryptography and more. It provides a solid foundation in the core concepts of cryptography, as well as insights into its practical applications.

By the end of this tutorial, you will have a basic understanding of how cryptography works and how it can be used to protect your information.