What is Cryptography? And Its Uses?

In order to avoid unauthorised access, modern cryptography is a technique for sending and receiving communications that only the intended recipient and sender can read. It frequently entails the encryption of electronic data, which frequently results in the creation of ciphertext by scrambling plain text. Then, it converts it back to readable format on the receiving end using some kind of decryption key. Asymmetric key systems, which are generally more secure, can be used in cryptography in addition to symmetric key systems, which are the most straightforward. Secure communication and electronic data are made possible by cryptography, which prevents nefarious enemies from reading, interpreting, or accessing it.

What is Cryptography?

Data and communications are protected using cryptography so that only the sender and the intended receiver may access them. It is a method of message security as well as the study of communications. Cryptography can ultimately prevent data from being changed or stolen. It can also be used to verify user identities. In order to keep electronic data and messages secure and readable by the intended parties only, cryptography frequently uses encryption and an algorithm. There has been cryptography for ages. The word “crypto” itself is derived from the Greek word “kryptos,” which means “hidden.” Today’s cryptography is built on principles from computer science and mathematics.

Types of Cryptography

Symmetric cryptography and asymmetric cryptography are the two primary types of encryption used for digital data and secure messages today. A third form of function doesn’t require the use of a key—hash functions.

• One of the most popular and straightforward methods for encrypting and decrypting electronic data is symmetric cryptography. Secret-key or private-key cryptography are other names for it. Both the sender and the recipient will have the same key in symmetric cryptography. On one end, this key is used to encrypt communications and data, while on the other, it is used to decrypt it. The secret key used for communication must be the same for both parties. Symmetric cryptography is quick, simple to use, and ideal for bulk encryption or data transmission. This type of encryption has the drawback that if a third party learns the secret key, they can read and decrypt the data or messages as well. The two most common types of symmetric encryption algorithms: stream and block algorithms.
  • Stream algorithm: This kind encrypts the data as it streams, so the system’s RAM is not used to store it. The RC4 (Rivest Cypher 4) is one of the most widely used stream cyphers, encrypting messages one byte at a time.  
  • Block algorithms: These use the secret key to encrypt particular bit lengths in blocks of data. While blocks are finished, the data is kept in the system’s memory. The most often used symmetric algorithm is called Advanced Encryption Standard (AES). Cryptographic keys of 128, 192, and 256 bits are used to encrypt and decrypt blocks of 128-bit data. Under the direction of the National Institute of Standards and Technology (NIST), the AES has received FIPS (Federal Information Processing Standards) approval.  
• Asymmetric cryptography uses two separate keys and is also known as public-key cryptography. To encrypt data, a public key is publicly disseminated to everyone. This key is necessary to encrypt and send communications. To encrypt the data, a sender might ask the recipient for their public key. The communication will then need to be decrypted using the private key, which is kept a secret. The private key and public key pair are mathematically connected. To carry out activities, send and receive encrypted data and messages, and access sensitive data, both keys are required. Asymmetric cryptography is frequently employed on a smaller scale since it requires more processing power and longer keys, with data chunks that are smaller than the key. A cryptosystem can use both symmetric and asymmetric cryptography. For instance, symmetric cryptography is used to transport or encrypt larger volumes of data, whereas asymmetric cryptography can be used to encrypt symmetric keys.  
• A third kind of cryptography that does not require a key is hash functions. Based on the plain text message, a fixed length hash value is used. The message can then be used to verify that it hasn’t been tampered with or compromised using this. Since the hashed output cannot be reversed to disclose the input data, hash functions add an additional degree of protection.  

What is the Purpose of Cryptography?

With the use of encryption, data and messages are kept safe and off-limits to potential threats and bad actors. It frequently operates in the background to encrypt and decrypt data you send through email, social media, applications, and website interactions.

You can use symmetric cryptography for the following things:

• Applications for payments and card transactions
• production of random numbers
• Verifying the sender’s signature to make sure they are who they say they are

Uses for asymmetric cryptography include the following:

• using emails
• SMS card verification
• Web safety
• Private key exchange

The Fundamentals of Cryptography

In order to prevent digital information from being changed, accessed, or read by anybody other than those with authorised access, cryptography aims for private communications and data security. These are some fundamental ideas in cryptography:

1. Confidentiality: The foundation of cryptography depends on the data being protected from outside parties or nefarious enemies. Specific restrictions and standards are included in confidentiality agreements to ensure that information is protected, secure, and only available to specific individuals or within specific contexts.
2. Encryption: To preserve privacy when sending communications or data between a sender and a receiver, encryption transforms readable material into an unreadable form. Typically, an algorithm is used to do this.  
3. Decryption: Decryption is the opposite of encryption; it involves restoring the data to its original, readable form. Usually, a specific key is used for this; this key may be used for both encryption and decryption or it may require two keys.  
4. Data consistency and correctness must be maintained throughout the lifetime of the data, and data integrity can assist in preserving this accuracy. At any point along the communication chain, data cannot be changed. Everything between the sender and the recipient must remain unbroken.
    
5. Authentication: This establishes that the data or message received is actually from the source that it claims to be. It is frequently necessary for the sender to prove that they are the true author of the message that the recipient has received.  
6. Non-repudiation: The capacity to prevent the creator of a communication or piece of data from contesting the veracity of their signature. The use of digital signatures can make it impossible for the sender or creator of a communication to retract it.