Last Updated on April 13, 2023 by Prepbytes

Every human activity nowadays revolves around computer systems. This computing technology is used in a variety of applications, including healthcare, education, banking, software, and marketing. However, you may be wondering how businesses safeguard their data. "Cryptography" is the answer to this question. Cryptography has played a crucial role in shaping the modern information age and is essential for protecting sensitive information in today’s connected world. Let us study Cryptography and Types of Cryptography in detail.

## What is Cryptography?

Cryptography is the practice of secure communication in the presence of third parties, called adversaries. It involves transforming information, called plaintext, into a form that is unreadable and can only be transformed back to its original form by someone who has the proper key, or knowledge, to do so.

Cryptography has been used for centuries to secure communication, with the earliest recorded use being the scytale, a rod used by the Ancient Greeks to encrypt messages by wrapping a strip of parchment around it. The invention of the modern computer has made cryptography more important than ever, as it is now used to secure not just military communications but also internet transactions and data storage.

### Some Common Cryptography Examples

These are the cryptography examples :

**Secure Web Browsing:**When you visit a website with "https" in the URL, the communication between your browser and the website is encrypted using SSL/TLS, which is a form of symmetric key cryptography.**Online Banking:**Many online banking systems use cryptography to secure sensitive financial transactions and protect customers’ personal and financial information.**Email:**Many email services use encryption to protect the privacy and confidentiality of emails in transit. For example, services like Gmail use Transport Layer Security (TLS) to encrypt emails.**Mobile Devices:**Mobile devices, such as smartphones and tablets, often use cryptography to secure data stored on the device and to protect communications. For example, Apple’s iOS uses a hardware encryption system to secure data on iPhones and iPads.**Cloud Storage:**Cryptography is used to secure data stored in the cloud. For example, Amazon Web Services uses the AES encryption algorithm to secure data stored in its Simple Storage Service (S3) and the Amazon Elastic Block Store (EBS).

These are just a few cryptography examples that are widely used in many other areas including VPNs, secure instant messaging, and software updates to name a few

## Features of Cryptography

These are the features of cryptography :

**Confidentiality:**Hides the contents of a message from unauthorized parties.**Integrity:**Ensures that a message has not been altered during transmission.**Authentication:**Verifies the identity of the sender and receiver of a message.**Non-repudiation:**Prevents the sender from denying having sent a message.**Availability:**Ensures that authorized users have access to the information they need when they need it.**Key Management:**The process of generating, distributing, storing, and replacing cryptographic keys.**Algorithm:**The mathematical formula used to encrypt and decrypt messages.**Encryption/Decryption:**The process of converting plaintext to ciphertext and vice versa.**Symmetric/Asymmetric Key Encryption:**The use of a single shared key for encryption and decryption or the use of a public and private key pair.**Hash Functions:**A one-way mathematical transformation of an input (message) into a fixed-size output (message digest).**Digital Signatures:**A signature that can be used to authenticate the identity of the sender of a message and ensure the integrity of the message.

## Types of Cryptography

There are Three Types of Cryptography

### Symmetric Key

The symmetric key is a types of cryptography which also known as private key cryptography or secret key cryptography. Both the information receiver and the sender use a single key to encrypt and decrypt the message in this case. it is a method of encryption and decryption that uses a single shared key for both operations. The same key is used to encrypt the plaintext into ciphertext and to decrypt the ciphertext back into plaintext.

AES is the most commonly used type of cryptography in this method (Advanced Encryption System). The approaches used in this type are completely streamlined and faster as well.

#### Symmetric key cryptography includes the following types:

- Block
- Block cipher
- DES (Data Encryption System)
- RC2
- IDEA
- Blowfish
- Stream cipher

#### Advantages of Symmetric Key Cryptography include:

**Speed:**Encryption and decryption are fast and efficient, making it suitable for large amounts of data.**Simplicity:**The single shared key makes it easier to implement and use compared to asymmetric key cryptography.

#### Disadvantages of Symmetric Key Cryptography include:

**Key Management:**The secure distribution of the shared key between the sender and receiver can be a challenge.**Scalability:**With a large number of users, the number of keys required can quickly become unmanageable.**Security:**If the shared key is compromised, the confidentiality and integrity of the data can be threatened.

### Asymmetric Key

The asymmetric key is types of cryptography which also known as public-key cryptography. It employs a diverse and secure method of information transmission. The most common type of cryptography used in this method is RSA. An asymmetric key refers to a cryptographic method that uses two different keys for encryption and decryption. The two keys are called the public key and the private key. The public key is used to encrypt the data and the private key is used to decrypt it. The security of this method is based on the fact that it is computationally infeasible to derive the private key from the public key. Asymmetric key cryptography is commonly used for secure communication, digital signatures, and public key infrastructure (PKI).

#### Asymmetric Key Cryptography includes the following types:

- RSA
- DSA
- PKCs

#### Advantages of Asymmetric Key Cryptography:

**Increased security:**The use of two different keys makes it more secure than symmetric key cryptography.**Non-repudiation:**The digital signature created using the private key provides proof of the authenticity of the sender.**Scalability:**Asymmetric key cryptography can support a large number of users.**Public key distribution:**The public key can be freely distributed without any security risk, allowing for easy encryption of messages.

#### Disadvantages of Asymmetric Key Cryptography:

**Computational overhead:**The encryption and decryption process using asymmetric key cryptography is slower and more resource-intensive compared to symmetric key cryptography.**Key management:**Asymmetric key cryptography requires the safekeeping and management of both private and public keys.**Key length:**The security of asymmetric key cryptography is directly proportional to the length of the key used. Longer keys require more processing power, making them less practical for some applications.**Lack of standardization:**Asymmetric key cryptography is still evolving and there is a lack of standardization in terms of algorithms and key lengths, making it difficult for interoperability between different systems

## Hash Function

Types of cryptography in which an algorithm followed by a hash function take an arbitrary length of the message as input and returns a fixed length of the output. It is also referred to as a mathematical equation because it uses numerical values as input to generate the hash message. This method does not require a key because it operates in a one-way scenario. Each round of hashing operations considers input as an array of the most recent block and generates the last round of activity as output.

Some of the hash’s features include:

- Message Digest 5 (MD5)
- RIPEMD
- Whirlpool
- SHA (Secure hash Algorithm)

## Applications of Cryptography

These are the application of Cryptography:

**Secure Communications:**Cryptography is widely used to secure communications over the internet, such as email, instant messaging, and virtual private networks (VPNs).**Data Protection:**Cryptography is used to protect sensitive data, such as financial information, medical records, and government secrets, from unauthorized access,all these are cryptography examples.**E-commerce and Online Transactions:**Cryptography is used to secure online transactions, such as online shopping and banking, to protect sensitive information and prevent fraud.**Authentication:**Cryptography is used to authenticate the identity of users and devices, such as digital certificates, biometric authentication, and smart cards.**Cloud Computing:**Cryptography is used to secure cloud computing services, such as data storage and processing, by encrypting data and controlling access.**Wireless Networks:**Cryptography is used to secure wireless networks, such as Wi-Fi, from unauthorized access and data interception.**Disk Encryption:**Cryptography is used to secure data stored on disk drives, such as full-disk encryption and encrypted file systems, to prevent unauthorized access.**Mobile Devices:**Cryptography is used to secure mobile devices, such as smartphones and tablets, to protect sensitive data and prevent unauthorized access.**Digital Rights Management:**Cryptography is used to protect the rights of copyright holders by controlling the distribution and usage of digital content, such as music, movies, and software.

**Conclusion**

Cryptography is the practice of converting information into a coded form to prevent unauthorized access and ensure its privacy and confidentiality. It is used in various fields such as computer security, communications, and financial transactions to secure sensitive information from prying eyes.

Some common types of cryptography are:

- symmetric-key cryptography
- asymmetric-key cryptography
- Hashing.

Cryptography involves the use of mathematical algorithms and protocols to encode, transmit and decode data, and often relies on secret keys to ensure its security.

## Frequently Asked Questions (FAQ)

Here are some Frequently Asked Questions related to “Cryptography and Types of Cryptography”.

**Question 1: What is cryptography?**

**Answer:** Cryptography is the practice of transforming information in a way that makes it unreadable to anyone except those for whom it is intended. It is used for secure communication and to protect sensitive information from unauthorized access.

**Question 2: What is the difference between symmetric and asymmetric types of cryptography?**

**Answer:** Symmetric cryptography uses the same key for both encryption and decryption, while asymmetric cryptography uses two different keys, a public key for encryption and a private key for decryption.

**Question 3: What is a digital signature?**

**Answer:** A digital signature is a mathematical mechanism used to verify the authenticity of digital data. It is created using the sender’s private key and can be verified using their public key.

**Question 4: What is a hash function?**

**Answer:** A hash function is a one-way mathematical function that takes an input (or "message") and returns a fixed-size string of characters, which is usually a "digest" that is unique to the unique values of the input.

**Question 5: What is the purpose of a key in cryptography?**

**Answer:** A key is used in cryptography to encrypt and decrypt data. The key determines the transformation of the original message into the encrypted message and vice versa.

**Question 6: What is a cipher?**

**Answer:** A cipher is an algorithm for encrypting and decrypting data. It defines the rules for transforming plaintext into ciphertext and back.

**Question 7: What is the most commonly used symmetric cipher?**

**Answer:** The Advanced Encryption Standard (AES) is the most commonly used symmetric cipher.

**Question 8: What is the most commonly used asymmetric cipher?**

**Answer:** The RSA algorithm is the most commonly used asymmetric cipher.