Knowing the Differences Between Symmetric and Asymmetric Cryptography in Encryption Algorithms

Encryption is the foundation of cybersecurity in today’s digital world, safeguarding everything from private business communications to online banking transactions. It is crucial for IT professionals working in cybersecurity or aiming for CompTIA Security+ certification to comprehend the basic distinctions between symmetric and asymmetric encryption algorithms. This article explains these two essential encryption techniques, their applications, and why both are frequently needed for modern security.

Fundamentally, encryption is the process of using mathematical algorithms and keys to transform readable data (plaintext) into an unreadable format (ciphertext). The data cannot be decrypted back to its original form unless the right key is used. Consider it an advanced digital information lock-and-key system.

One key is used for both encryption and decryption in symmetric encryption, also known as secret key encryption. It’s similar to having a single key that can be used to unlock and lock a door. The same secret key must be owned by everyone who needs to access the encrypted data.

The gold standard for symmetric encryption is AES (Advanced Encryption Standard), which comes with key lengths of 128, 192, and 256 bits. Because of its strong security, governments and businesses use AES-256 extensively.

DES and 3DES: Triple DES (3DES) uses the DES algorithm three times and is still used in some legacy systems, whereas DES (Data Encryption Standard) is now regarded as outdated because of its 56-bit key length.

Although they are less frequently used than AES in contemporary implementations, the algorithms Blowfish and Twofish are renowned for their speed and variable key lengths.

Because of its effectiveness on devices without hardware acceleration, ChaCha20 is a stream cipher that is becoming more and more popular, particularly in mobile applications.

A public key for encryption and a private key for decryption are two mathematically related keys used in asymmetric encryption, also known as public key cryptography. It’s similar to having a mailbox that anyone can use to deposit mail (public key), but that only you have the private key to open.

The most popular asymmetric algorithm is RSA (Rivest-Shamir-Adleman), which usually uses keys with 2048 or 4096 bits. The mathematical challenge of factoring large prime numbers is the foundation of RSA.

Elliptic Curve Cryptography (ECC): More effective for mobile devices and Internet of Things applications, ECC offers comparable security to RSA with smaller key sizes.

Based on the discrete logarithm problem, the DSA (Digital Signature Algorithm) is primarily used for digital signatures as opposed to encryption.

Diffie-Hellman: It allows safe key sharing over unprotected channels and is technically a key exchange protocol rather than an encryption algorithm.

In reality, contemporary secure communications employ a hybrid strategy that combines the two forms of encryption:

This is precisely how HTTPS/TLS functions. When a secure website is accessed:

Key Length Is Important: Longer keys typically result in slower performance but stronger encryption. Current suggestions:

Algorithm Lifecycle: There is a lifespan for encryption algorithms. Keep up with new standards (like post-quantum cryptography) and deprecations (like DES).

Implementation Quality: Bad implementation can weaken even powerful algorithms. Instead of creating your own cryptographic libraries, use proven ones.

Existing asymmetric algorithms may be threatened by the development of quantum computers. To get ready for this future, NIST is standardizing algorithms that are resistant to quantum errors. With adequate key lengths, symmetric algorithms such as AES-256 are regarded as quantum-resistant.

Knowing the difference between symmetric and asymmetric encryption is not only academic; it is also useful information that affects day-to-day security choices. Understanding when and how to use each type of encryption is essential, whether you’re building secure systems, setting up VPNs, or putting API security into practice.

Candidates for Security+ should concentrate on comprehending the common algorithms, practical applications, and conceptual distinctions. The best balance between security and performance is achieved by hybrid approaches that use both symmetric and asymmetric encryption. Keep in mind that modern security rarely employs just one type.

Although the field of encryption is constantly changing, the fundamental ideas of symmetric and asymmetric encryption are still essential knowledge for any cybersecurity professional. As threats develop, try to make it easier to read, more relatable, and more akin to teaching and educating someone. Edit: Plan out rewriting the article to make it more interesting and educational.3m, 14s The user requests that I rewrite the encryption article to be:

Simpler to read
More conversational and human
More emphasis on instruction and training

I ought to:

Many of my Security+ students are surprised to learn that you use both symmetric and asymmetric encryption on a daily basis, most likely without even realizing it. These two encryption techniques cooperate to protect your data each time you send a WhatsApp message, check your email, or shop online.

I’m going to explain these ideas in a way that makes sense today. No complicated mathematical formulas, just useful information.

Encryption can be thought of as a method of jumbling your message so that only the appropriate individual can decipher it. It’s similar to writing a note in a code that only you and your friend can figure out.

The “code book” that we use to jumble and decipher messages? We refer to that as a key. This is where our two encryption types are useful.

Suppose that the keys to the same lockbox are the same for you and your friend. If you lock something inside, your friend can use the same key to unlock it. That’s symmetric encryption, where your data is encrypted (locked) and decrypted (unlocked) using a single shared key.

Suppose you are using a password to encrypt a file on your computer. The key created by that password jumbles your file. You’ll need that same password to decipher it later. Easy, isn’t it?

The star is AES (Advanced Encryption Standard). AES is most likely at work when you connect to WiFi, encrypt your phone, or use a password manager. There are three flavors available:

Older Players: DES and 3DES may be found in older systems, but they are no more useful than flip phones in 2024.

The fact is that symmetric encryption is QUICK. incredibly quick. Symmetric encryption is used when Netflix streams a movie to your device because it can manage that enormous volume of data without experiencing any lag.

It’s easy, too. One important, simple procedure that requires little processing power. It won’t deplete your smartphone’s battery.

“How do you safely share that key in the first place?” is the most important question my students ask.

Consider it. I must find a way to give you the key if I wish to send you an encrypted message. However, when I send the key to you, it could be stolen if someone is observing our conversations. If you try to mail someone a key to a lockbox, what if the mail is intercepted?

This issue is known as the key distribution problem, which is why we require…

This is where the interesting part begins. What if you had two keys that were mathematically related but different? The public key locks the box, while the private key unlocks it.

It’s similar to having a mailbox on your street:

The following occurs when you visit a secure website (notice the padlock in your browser):

A hacker cannot use the public key for any purpose, even if they manage to intercept it. The private key, which never leaves the website’s server, would be necessary.

RSA: The seasoned individual. It has remained active since the 1970s. RSA is used in the majority of SSL certificates.

The new favorite is the Elliptic Curve (ECC). It is ideal for phones and Internet of Things devices because it performs the same function as RSA but uses smaller keys.

Symmetric encryption is unable to identify the sender of a message. Asymmetric encryption allows you to “sign” a message with your private key, allowing anyone with your public key to confirm that it was indeed sent by you. It’s comparable to having an unforgeable signature.

Do you recall how fast symmetric encryption is? Asymmetric, on the other hand, is roughly a thousand times slower. Using RSA to encrypt a large file would be like using a teaspoon to empty a swimming pool.

The best part is that we are not forced to make a decision! Both kinds are combined in modern systems, which capitalize on the advantages of each approach.

I’ll give you a practical example to demonstrate how this works:

Keep in mind these important points:

Importantly, you can use encryption effectively without being a mathematician. The tools you use already have the algorithms built in. It is your responsibility to:

Let’s see if this works. Are you able to respond to these?

(The responses are as follows: 1-symmetric for speed, 2-asymmetric to eliminate the need for clients to share keys, 3-asymmetric for safe key exchange, and symmetric for real data transfer.)

It’s not necessary to be afraid of encryption. Consider Symmetric as your workhorse; it’s quick, effective, and ideal for large tasks where you can safely share keys. Consider asymmetric as your personal security guard; it manages introductions, confirms identities, and establishes safe channels.

They work together to build the safe online environment we depend on on a daily basis. If you grasp these ideas, you will not only pass the Security+ test but also gain an understanding of the security framework that guards our digital lives.

Keep in mind that everyone started out as a beginner. You’re ahead of many IT professionals who merely memorize without really understanding because you’re taking the time to learn these basics. You’ll succeed in cybersecurity if you maintain your curiosity!