The growth of the digital age has led to a corresponding increase in the need to transmit and store data online. However, there is the risk of people having unauthorized access to your private and sensitive information. Thankfully, cryptography is a technology that makes it possible to secure your online communication.
So, what exactly is cryptography, why is it important, and what are its various types? Keep reading this article to understand all these and much more! Let’s dive right in!
KEY TAKEAWAYS:
- Cryptography or encryption involves converting online information into a form that cannot be accessed by an unauthorized person.
- Encryption is important for data protection and integrity, authentication, and secure communication.
- Types of cryptography include symmetric-key and asymmetric-key cryptography and hash functions.
- Some common modern applications of cryptography are online banking and e-commerce, cryptocurrencies, email security, and virtual private networks (VPNs).
What Is Cryptography?
Cryptography refers to the process of securing information by converting it into a format that is either unreadable or inaccessible to unauthorized people. The goal of this practice is to protect data from being altered when it is stored or transmitted. In simple terms, cryptography works by converting a readable information (plaintext) into an encoded message (ciphertext) through encryption. Anyone with the correct decryption key can then reconvert the ciphertext to see the original message.
The origin of cryptography or encryption can be traced back to ancient times when codes were used to send sensitive messages during war times. Today, it is an important part of every digital security system to ensure safe communication between devices and people.
Importance of Cryptography
Now that you have a basic understanding of what cryptography is, let us examine its role in the digital world.
- Data protection: When you send sensitive data like your credit card details or classified business documents over a network, encryption allows only the recipient to access it. This function is of great importance in the finance, health care, and government sectors.
- Data integrity: Cryptography prevents data from being tampered with in transit. If your message has been modified before it got to you, this technology will inform you.
- Authentication: Encryption helps with verifying the identity of a user, device, or a system. As such, it prevents issues like fraud, phishing, and identity theft. Also, it provides a function called non-repudiation that proves who the sender of a message is.
- Secure communication: Cryptography prevents your message from being read by hackers or scammers when using emails, chats, and other messaging applications.
Types of Cryptography
Cryptography is made up of several types that serve different functions. However, the most common ones are:
Symmetric-Key Cryptography
This is also known as private-key or secret-key cryptography. Here, the sender encrypts data using a shared key, the receiver then uses the same key to decode it. You have to keep the key a secret because anyone who has it can access the message. Symmetric-key cryptography is generally faster, which makes it useful in protecting large volumes of data.
Examples
- Advanced Encryption Standard (AES): AES is considered one of the most secure encryption with key sizes of either 128, 192, or 256 bits.
- Data Encryption Standard (DES): DES is an older cryptography type that has been replaced by AES because of its security vulnerabilities.
- Triple DES (3DES): Uses three times the regular DES for increased security.
Asymmetric-Key Cryptography
This is also known as public-key encryptions, and it uses a pair of one public and one private key. The public key, which can be freely shared) encrypts information while the corresponding private one (which is kept confidential) decrypts it. It works by the sender encrypting a message using the recipient’s public key while the receiver interprets the information with their private key. The downside to this type of encoding is that it is slower than the symmetric kind because it involves more complex maths algorithms.
Examples
- Rivest-Shamir-Adleman (RSA): Used to secure emails and digital signatures.
- Elliptic Curve Cryptography(ECC): Works just like RSA but with a shorter key length.
- Digital Signature Algorithm(DSA): Also used to ensure the authenticity and integrity of digital signatures.
Hash Functions
Hash functions do not involve using keys. Instead, it takes a message and converts it to a fixed string of characters that is unique to the input. As such, even the slightest change to the input will cause a significant change in the hash. This cryptography is fast and efficient, which makes it useful in decentralized applications.
Examples
- Secure Hash Algorithm (SHA-256): SHA-256 is commonly used for digital certificates and in blockchain technology.
- Message Digest Algorithm 5 (MD5): Used to be the most popular hash function but is not considered insecure because of its vulnerabilities.
Modern Applications of Cryptography
Some common applications of cryptography include:
- Online banking and e-commerce.
- Smart contracts and cryptocurrencies.
- Email security.
- Virtual private networks (VPNs).
- Secure messaging.
- Health care.
- Government and military.
In Summary
Cryptography has touched almost every area of our lives today because it ensures that our online communication is secure. However, it is important to note that this technology is not without its challenges. Human errors and compromise due to exposure of public and private keys can happen. Luckily, research is still ongoing in the field to provide more digital security for everyone.
References
- Liddell, Henry George; Scott, Robert; Jones, Henry Stuart; McKenzie, Roderick (1984). A Greek-English Lexicon. Oxford University Press.
- Rivest, Ronald L. (1990). “Cryptography”. In J. Van Leeuwen (ed.). Handbook of Theoretical Computer Science. Vol. 1. Elsevier.
- Bellare, Mihir; Rogaway, Phillip (21 September 2005). “Introduction”. Introduction to Modern Cryptography.
