Cryptography and its Types

Cryptography is a technique of securing information and communications using codes to ensure confidentiality, integrity and authentication. Thus, preventing unauthorized access to information. The prefix "crypt" means "hidden" and the suffix "graphy" means "writing". In Cryptography, the techniques that are used to protect information are obtained from mathematical concepts and a set of rule-based calculations known as algorithms to convert messages in ways that make it hard to decode them. These algorithms are used for cryptographic key generation, digital signing, and verification to protect data privacy, web browsing on the internet and to protect confidential transactions such as credit card and debit card transactions.

Features Of Cryptography

The features of cryptography that makes it a popular choice in various applications could be listed down as:

1. Confidentiality: Information can only be accessed by the person for whom it is intended and no other person except him can access it.
2. Integrity: Information cannot be modified in storage or transition between sender and intended receiver without any addition to information being detected.
3. Non-repudiation: The creator/sender of information cannot deny his intention to send information at a later stage.
4. Authentication: The identities of the sender and receiver are confirmed. As well destination/origin of the information is confirmed.
5. Interoperability: Cryptography allows for secure communication between different systems and platforms.
6. Adaptability: Cryptography continuously evolves to stay ahead of security threats and technological advancements.

How Does a Cryptographic Key Work?

As we all know that cryptography technique is use to convert plain text into ciphertext. This technique is done by cryptographic key. Basically cryptographic key is a string of characters which is used to encrypts the data and decrypt the data.

"Geeks for Geeks" + ⚿ = "HYMeAS90#"

For example- "Geeks for Geeks" is a plaintext and convert into ciphertext "HYMeAS90#" with the help of cryptographic key.

Types Of Cryptography

There are three types of cryptography, namely Symmetric Key Cryptography, Asymmetric Key Cryptography and Hash functions, here's a detailed explanation below:

1. Symmetric Key Cryptography

Symmetric Key Cryptography is an encryption system where the sender and receiver of a message use a single common key to encrypt and decrypt messages. Symmetric Key cryptography is faster and simpler but the problem is that the sender and receiver have to somehow exchange keys securely. The most popular symmetric key cryptography systems are Data Encryption Systems (DES) and Advanced Encryption Systems (AES) .

2. Hash Functions

There is no key required in hash function cryptography as it uses mathematical equations to genrate a hash message for nay arbitrary length of message, and the output will be of fixed length. Some of the famous hash function are:

• SHA-256
• MD5
• MD6

3. Asymmetric Key Cryptography

In Asymmetric Key Cryptography , a pair of keys is used to encrypt and decrypt information. A sender's public key is used for encryption and a receiver's private key is used for decryption. Public keys and Private keys are different. Even if the public key is known by everyone the intended receiver can only decode it because he holds his private key. The most popular asymmetric key cryptography algorithm is the RSA algorithm.

Applications of Cryptography

Cryptography has wide area of applications in the modern world, where the technology is rapidly evolving. From authentication measures to cryptocurrencies, cryptography is here to stay, these are some of the most common applications of cryptography listed below:

• Computer passwords: Cryptography is widely utilized in computer security, particularly when creating and maintaining passwords. When a user logs in, their password is hashed and compared to the hash that was previously stored. Passwords are hashed and encrypted before being stored. In this technique, the passwords are encrypted so that even if a hacker gains access to the password database, they cannot read the passwords.

• Digital Currencies: To protect transactions and prevent fraud, digital currencies like Bitcoin also use cryptography. Complex algorithms and cryptographic keys are used to safeguard transactions, making it nearly hard to tamper with or forge the transactions.

• Secure web browsing: Online browsing security is provided by the use of cryptography, which shields users from eavesdropping and man-in-the-middle assaults. Public key cryptography is used by the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols to encrypt data sent between the web server and the client, establishing a secure channel for communication.

• Electronic Signatures: Electronic signatures serve as the digital equivalent of a handwritten signature and are used to sign documents. Digital signatures are created using cryptography and can be validated using public key cryptography. In many nations, electronic signatures are enforceable by law, and their use is expanding quickly.

• Authentication: Cryptography is used for authentication in many different situations, such as when accessing a bank account, logging into a computer, or using a secure network. Cryptographic methods are employed by authentication protocols to confirm the user's identity and confirm that they have the required access rights to the resource.

• Cryptocurrencies: Cryptography is heavily used by cryptocurrencies like Bitcoin and Ethereum to protect transactions, thwart fraud, and maintain the network's integrity. Complex algorithms and cryptographic keys are used to safeguard transactions, making it nearly hard to tamper with or forge the transactions.

• End-to-end Internet Encryption: End-to-end encryption is used to protect two-way communications like video conversations, instant messages, and email. Even if the message is encrypted, it assures that only the intended receivers can read the message.  End-to-end encryption is widely used in communication apps like WhatsApp and Signal, and it provides a high level of security and privacy for users.

Types of Cryptography Algorithm

Cryptography Algorithms can be classified into several categories based on the way they utilize and manage their keys, their efficiency and workflow, here are the most common algorithms

• Advanced Encryption Standard (AES): AES (Advanced Encryption Standard) is a popular encryption algorithm which uses the same key for encryption and decryption It is a symmetric block cipher algorithm with block size of 128 bits, 192 bits or 256 bits. AES algorithm is widely regarded as the replacement of DES (Data encryption standard) algorithm.

• Data Encryption Standard (DES): DES (Data encryption standard) is an older encryption algorithm that is used to convert 64-bit plaintext data into 48-bit encrypted ciphertext. It uses symmetric keys (which means same key for encryption and decryption). It is kind of old by today’s standard but can be used as a basic building block for learning newer encryption algorithms.

• RSA: RSA is an basic asymmetric cryptographic algorithm which uses two different keys for encryption. The RSA algorithm works on a block cipher concept that converts plain text into cipher text and vice versa.

• Secure Hash Algorithm (SHA): SHA is used to generate unique fixed-length digital fingerprints of input data known as hashes. SHA variations such as SHA-2 and SHA-3 are commonly used to ensure data integrity and authenticity. The tiniest change in input data drastically modifies the hash output, indicating a loss of integrity. Hashing is the process of storing key value pairs with the help of a hash function into a hash table.

Advantages of Cryptography

Cryptography has some remarkable features that makes it widely adapted all over the world in different technologies, here are few points that makes it stand out:

• Cryptography can be used for access control to ensure that only parties with the proper permissions have access to a resource.
• For secure online communication, it offers secure mechanisms for transmitting private information like passwords, bank account numbers, and other sensitive data over the Internet.
• It helps in the defense against various types of assaults including replay and man-in-the-middle attacks.
• Cryptography can help firms in meeting a variety of legal requirements including data protection and privacy legislation.

Conclusion

Cryptography is used to secure information and communications by converting data into coded formats, ensuring confidentiality, integrity, and authentication. It is essential for a wide range of applications, including securing online transactions, web browsing, passwords, digital currencies, and authentication.

Cryptography continuously evolves to stay ahead of security threats, offering solutions such as symmetric key encryption (AES), asymmetric key encryption (RSA), and hash functions (SHA) to ensure data privacy and integrity.

With its widespread applications in fields like secure web browsing, cryptocurrencies, electronic signatures, and end-to-end encryption, cryptography plays a vital role in protecting sensitive data from malicious actors. As digital threats continue to rise, cryptography ensures that only authorized parties can access, modify, or transmit critical information securely.