- Cryptography Tutorial
- Cryptography - Home
- Cryptography - Origin
- Cryptography - History
- Cryptography - Principles
- Cryptography - Applications
- Cryptography - Benefits & Drawbacks
- Cryptography - Modern Age
- Cryptography - Traditional Ciphers
- Cryptography - Need for Encryption
- Cryptography - Double Strength Encryption
- Cryptosystems
- Cryptosystems
- Cryptosystems - Components
- Attacks On Cryptosystem
- Cryptosystems - Rainbow table attack
- Cryptosystems - Dictionary attack
- Cryptosystems - Brute force attack
- Cryptosystems - Cryptanalysis Techniques
- Types of Cryptography
- Cryptosystems - Types
- Public Key Encryption
- Modern Symmetric Key Encryption
- Cryptography Hash functions
- Key Management
- Cryptosystems - Key Generation
- Cryptosystems - Key Storage
- Cryptosystems - Key Distribution
- Cryptosystems - Key Revocation
- Block Ciphers
- Cryptosystems - Stream Cipher
- Cryptography - Block Cipher
- Cryptography - Feistel Block Cipher
- Block Cipher Modes of Operation
- Block Cipher Modes of Operation
- Electronic Code Book (ECB) Mode
- Cipher Block Chaining (CBC) Mode
- Cipher Feedback (CFB) Mode
- Output Feedback (OFB) Mode
- Counter (CTR) Mode
- Classic Ciphers
- Cryptography - Reverse Cipher
- Cryptography - Caesar Cipher
- Cryptography - ROT13 Algorithm
- Cryptography - Transposition Cipher
- Cryptography - Encryption Transposition Cipher
- Cryptography - Decryption Transposition Cipher
- Cryptography - Multiplicative Cipher
- Cryptography - Affine Ciphers
- Cryptography - Simple Substitution Cipher
- Cryptography - Encryption of Simple Substitution Cipher
- Cryptography - Decryption of Simple Substitution Cipher
- Cryptography - Vigenere Cipher
- Cryptography - Implementing Vigenere Cipher
- Modern Ciphers
- Base64 Encoding & Decoding
- Cryptography - XOR Encryption
- Substitution techniques
- Cryptography - MonoAlphabetic Cipher
- Cryptography - Hacking Monoalphabetic Cipher
- Cryptography - Polyalphabetic Cipher
- Cryptography - Playfair Cipher
- Cryptography - Hill Cipher
- Polyalphabetic Ciphers
- Cryptography - One-Time Pad Cipher
- Implementation of One Time Pad Cipher
- Cryptography - Transposition Techniques
- Cryptography - Rail Fence Cipher
- Cryptography - Columnar Transposition
- Cryptography - Steganography
- Symmetric Algorithms
- Cryptography - Data Encryption
- Cryptography - Encryption Algorithms
- Cryptography - Data Encryption Standard
- Cryptography - Triple DES
- Cryptography - Double DES
- Advanced Encryption Standard
- Cryptography - AES Structure
- Cryptography - AES Transformation Function
- Cryptography - Substitute Bytes Transformation
- Cryptography - ShiftRows Transformation
- Cryptography - MixColumns Transformation
- Cryptography - AddRoundKey Transformation
- Cryptography - AES Key Expansion Algorithm
- Cryptography - Blowfish Algorithm
- Cryptography - SHA Algorithm
- Cryptography - RC4 Algorithm
- Cryptography - Camellia Encryption Algorithm
- Cryptography - ChaCha20 Encryption Algorithm
- Cryptography - CAST5 Encryption Algorithm
- Cryptography - SEED Encryption Algorithm
- Cryptography - SM4 Encryption Algorithm
- IDEA - International Data Encryption Algorithm
- Public Key (Asymmetric) Cryptography Algorithms
- Cryptography - RSA Algorithm
- Cryptography - RSA Encryption
- Cryptography - RSA Decryption
- Cryptography - Creating RSA Keys
- Cryptography - Hacking RSA Cipher
- Cryptography - ECDSA Algorithm
- Cryptography - DSA Algorithm
- Cryptography - Diffie-Hellman Algorithm
- Data Integrity in Cryptography
- Data Integrity in Cryptography
- Message Authentication
- Cryptography Digital signatures
- Public Key Infrastructure

- Cryptography Useful Resources
- Cryptography - Quick Guide
- Cryptography - Discussion

# Cryptography Tutorial

## Cryptography Tutorial

The most common method for securing data transmissions in web applications or computer science projects is modern Cryptography. It is like a secret code language that helps to keep information safe.

This tutorial covers the basics of the Cryptography. It explains how programmers and network professionals can use cryptography to maintain the privacy of computer data. Starting with the origins of cryptography, it moves on to explain cryptosystems, various traditional and modern ciphers, public key encryption, data integration, message authentication, digital signatures and many more.

After finishing this course, you will be able to apply the fundamental principles of Cryptography to practical situations.

## Why to Learn Cryptography?

Imagine that you have got a secret message, and you only want certain people to crack the code. Cryptography comes to the rescue in the digital realm. It is like keeping your message into an unseen envelope that only the designated receiver can open.

Learning cryptography makes it fun and hands-on. You can create your own secret codes and understand how to decode others. And, it is a cool skill to have in today's digital age.

## Cryptography Applications

Cryptography has many practical applications which can be a valuable skill −

We can use cryptography for securing communication by encrypting the messages and emails.

Secondly we can use it for protecting our data in the applications by securing user data, like passwords and personal information.

Also you can secure file storage by securing confidential files and documents.

Next we can also use cryptography to secure our E-commerce platforms by securing online transactions and payment information.

We can also build blockchain technology by ensuring the security and integrity of transactions in blockchain-based systems.

Cryptography can also be used for password protection for storing and managing passwords securely.

And the most important thing is digital signatures for verifying the authenticity of digital messages or documents.

## Who Should Learn Cryptography?

Learning about cryptography is useful because you can use it in real life to keep information safe. There are lots of tools and help available for cryptography. If you learn it, you might find good jobs in cybersecurity because many companies need people who know how to keep data safe.

This tutorial is meant for students of computer science who aspire to learn the basics of cryptography. It will be helpful for networking professionals as well who would like to incorporate various cryptographic algorithms to ensure secure data communication over their networks.

## Prerequisites to Learn Cryptography

This tutorial has been prepared with the view to make it useful for almost anyone who is curious about cryptography. A basic knowledge of computer science and a secondary level of mathematics knowledge is sufficient to make the most of this tutorial.

Throughout this tutorial, you will learn the basics of cryptographic algorithms and its implementation in different languages. This tutorial is designed with an assumption that the user has an understanding of the basics of cryptography algorithms and basic programming knowledge.

Cryptography also involves solving problems logically. Develop your logical thinking skills to understand and create secure codes.

## FAQs about Cryptography

Now we will see some frequently asked questions (FAQ) about Cryptography in the below section −

Cryptography is the technique of concealing or encoding(changing its original form) the information in such a way that only the authenticated person can decode(get the original form) it. This technique of cryptography plays an important role in keeping our data safe. The data or information can be bank cards, computer passwords or online transactions and other private data.

Cryptography is very important in this modern world because it helps to protect your digital stuff from hackers by turning information into secret language or code.

Mathematicians and cryptographers create symmetric key encryption methods, like AES, with the goal that the ciphertext should be impossible to decrypt without the encryption key. This is true for current secure symmetric encryption algorithms (such as AES and ChaCha20), but it might not be true for other methods (such as DES and RC4), which are regarded as insecure symmetric encryption.

RC5, RC6, Camellia, ARIA, IDEA, Serpent, AES, ChaCha20, CAST, Twofish, and CAST are a few popular symmetric encryption algorithms. All of these methods are considered as secure when properly configured and applied.

Asymmetric-key cryptography is also called Public key cryptography. It is the cryptographic algorithm which uses pairs or related keys; the keys are known as public and private keys. Public key is used to encrypt the data and private key is used to decrypt the data.

And both the key pairs are generated using cryptographic algorithms. And the security of public key cryptography depends on keeping the private key secret and the public key can be shared and distributed publicly.

Although becoming a cryptographer usually requires a lengthy process, the field can pay more than average. An analytical problem-solver with good mathematical and computing abilities could find incredible fulfilment in cryptography.

Cryptographers have to keep up with the ever-evolving world of cyberthreats, thus they must regularly refresh their knowledge. The responsibilities of their profession can also vary daily, adding to its dynamic nature. The job can be difficult at times due to the significance of protecting sensitive digital data, as errors can result in breaches of privacy. To help you make a smart decision regarding this career, consider the benefits and drawbacks of being a cryptographer.

There are form main purpose of cryptography and they are given below −

Confidentiality

Integrity

Authentication

Non-repudiation

Here are some applications where we can use cryptography −

Authentication

Internet of Things

Card Payments

PC and different passwords

Ecommerce Websites

Digital currency

Secure file storage

Digital Signatures

It is impossible to prove that the algorithm is secure. The only algorithm that has been shown to be safe is a single-use pad, and for most practical purposes, it is useless. What you can do is run multiple tests on the algorithm to find weaknesses.

DES has been thoroughly tested for nearly 30 years, so the cryptographic community is confident that this algorithm is good. The simple test for implementing the algorithm is to store binary zeros on a string, then change one bit at a time, and see how these changes affect the ciphertext. If change patterns are found, you can be confident that the algorithm has made a mistake.

The ideal language for cryptography is something you may choose from a wide range of options. See the languages listed below to get started with the Cryptography −

You will need to master at least one (and usually more than one) programming language if cryptography is your area of interest. The top languages for cryptography are listed below −

Python

Go

Ruby

C++

C#

Java

PHP

Many people believe that Claude E. Shannon is the father of mathematical cryptography. Shannon authored a paper titled "A mathematical theory of cryptography" while he was employed at Bell Labs for a number of years. Written in 1945, the Bell System Technical Journal eventually published this essay in 1949. It is widely acknowledged that the development of modern cryptography began with this work.

Cryptography uses many types of technology to keep our data secure. There are some common technologies used in cryptography like special algorithms (AES or RSA), computer software created to encrypt and decrypt messages, key management, cryptographic libraries, public key infrastructure (PKI) and digital signatures.

Together, these technologies form a secure framework for protecting our sensitive information across digital networks and communications. This technology plays an important role in protecting our privacy and ensuring the authenticity and integrity of data transferred over the Internet. The sensitive data can be our passwords, emails, and online transactions.

One tool used to protect information through coding is called OpenSSL. It's really popular as it functions effectively and has numerous expert certifications. It is written in the computer language C, which presents a concern because it is not always safe against memory problems.

We chose to use the different language Rust to rewrite some portions of OpenSSL, such as its ability to read specific kinds of data, in order to make sure our security stays at the highest level. Rust helps with maintaining the strength of our security by being fast and preserving data in memory.