Asymmetric vs. Symmetric Encryption: What’s The Difference?

Encryption is complex. Things get even trickier when you introduce the different types – asymmetric and symmetric. Both help to secure your data and prevent third parties from snooping on your sensitive information. So how do they work? Which one is best, and which should you use?

We’ll explore everything you need to know about asymmetric and symmetric encryption, including how they work, their use cases, and their pros and cons. Don’t worry; This isn’t another explanation you read through only to feel more confused than when you started. We’ve turned the complex concepts into clear definitions so you can easily come to grips with the types of encryption. 

What Is Encryption?

Before we go into the encryption types, let’s look at what encryption is and how it works. Encryption is a security method that masks your data and stops information from falling into the wrong hands. 

Let’s explore encryption in the context of VPNs. VPNs use encryption to secure your connection and hide your traffic from third parties. When you connect to a VPN, it establishes a secure tunnel between your device and the VPN server. This is called tunneling.

Once the tunnel is set up, the VPN breaks your data into small pieces called data packets. VPN encryption uses cryptography to change readable data, like your online searches, into unreadable text using a complicated algorithm. 

This unreadable text is called ciphertext. Anyone trying to snoop on your online activity can only see the cipher text, which means nothing. It’s like trying to read a book in a foreign language – nothing makes sense. 

Everything you do while connected to a VPN travels through the tunnel. The VPN tunnel is encrypted, as is every data packet. This means VPNs encrypt your data twice. 

You need a secret key to decrypt the information and turn the ciphertext back into readable text. This prevents random third parties from undoing the encryption and reading your information. Keys work slightly differently depending on whether the encryption is asymmetric or symmetric.

It sounds complex, but a VPN handles all of this automatically. You don’t need to remember keys to decrypt and encrypt your data. All you need to do is turn the VPN on. CyberGhost VPN encrypts your data as soon as you connect to transfer your data securely. 

What Is Symmetric Encryption?

Symmetric encryption relies on a single secret key to encrypt and decrypt your data. The same key is used to change your data from plaintext to ciphertext, and vice versa. Both the sender and receiver have the key to encrypt and decrypt the data. These keys are known as public keys.

First, the data is encrypted using an algorithm and the symmetric public key. This changes the plaintext into ciphertext, making it unreadable to anyone without the key. The data then travels over the internet to the decryption server at the destination. Here, it’s decrypted with the same public key to change it back from ciphertext to plaintext. This makes the data readable again.

It’s like sending your friend a private text message. You lock the text message with a passcode to keep it secure until it reaches your friend’s phone. The text message is also changed into random words so that it doesn’t make sense. Your friend can then use the same passcode to unlock the message and change it back into readable text. 

It’s important to keep the passcode secret. Otherwise, anyone could unlock the message and read your text. For example, you might share the passcode via an email that’s also password-protected. This makes sure both you and your friend have the right passcode for the text message, and no one else can find out what it is. 

This passcode is then stored securely on their phone so your friend can read other secret text messages you send. This is why asymmetric encryption is usually used with symmetric encryption to send the public key securely.

Symmetric encryption is one of the oldest methods of encryption. It’s often used to secure high volumes of sensitive data, such as private messages and payment applications. It’s also used to secure stored data, such as encrypted files within the cloud or on a shared server.

Symmetric Encryption: The Pros and Cons

Pros	Cons
👍🏻Secures data and stops others from viewing sensitive information 👍🏻Can be faster than asymmetric encryption  👍🏻Less resource-intensive than asymmetric encryption 👍🏻Widely used by most platforms, so is typically compatible with many devices 👍🏻Simple to use, relying on one key to encrypt and decrypt data	👎🏻Keys could be compromised, allowing unauthorized access to data 👎🏻Can be challenging to share the symmetric key securely without others seeing it 👎🏻Reusing the same key regularly could make it more prone to attack

One of the biggest advantages of symmetric encryption is its speed. It can secure large amounts of data quickly with a single key. These keys are short, so it takes less time to decrypt them. It’s also easy to implement and use because only one key is needed to secure the data. 

Using one short key has its disadvantages, though. The same key must be securely shared and stored, otherwise it can become compromised. This would allow unauthorized users to access the data you’re trying to hide. 

It can also be difficult to share the symmetric key between the sender and receiver without it being seen. This is why most organizations use a combination of symmetric and asymmetric encryption, especially for securely sharing the key.

What Is Asymmetric Encryption?

Asymmetric encryption uses different keys to encrypt and decrypt your data. It’s more complex than symmetric encryption, but it’s generally considered more secure. Asymmetric encryption relies on a combination of public and private keys. 

Unlike symmetric encryption, both the sender and receiver have unique keys. The receiver needs both a public and a private key to decrypt your data.

Let’s revisit the text message analogy again with asymmetric encryption. You want to send your friend a secret text message and lock it with a passcode. Rather than choosing a password, you ask your friend to give you a password. This is the public symmetric key. You lock the text message with the password your friend gave you and send it to them.

Once your friend has received the message, they’ll need the password they gave you to unlock it. They also need another password, known as a private key, to decrypt the message and read it. This could be a unique code sent to their phone after they open the message or a signature they enter alongside the password. 

Using asymmetric encryption helps to keep your data even more secure since it doesn’t matter if someone else has the public key. Even if someone found out your friend’s password, they’d still need to enter the second password to read the message.

Asymmetric encryption is typically used when extra security and authentication is crucial. For example, verifying the integrity of digital documents with a signature. RSA is a type of asymmetric encryption often used to encrypt emails. VPNs also use asymmetric encryption to establish secure connections between your device and the VPN server.

Asymmetric Encryption: The Pros and Cons

Pros	Cons
👍🏻Requires extra authentication to increase security 👍🏻No need to share the private key, reducing the risk of interception 👍🏻Public key can be shared without risking the security of data	👎🏻Can be slower than symmetric encryption 👎🏻More draining on resources due to the added private key 👎🏻More complex to use than symmetric encryption

Since asymmetric uses both private and public keys, the public key can be shared freely without risking the security of your data. Even if someone can see the public key, they still can’t read any information you send because they don’t have the private key to decrypt it. This makes asymmetric encryption highly secure for digital communications, reducing the risk of a third party intercepting your data and reading your information. 

Asymmetric encryption also requires additional authentication. It uses a private key to verify the sender’s identity and ensure the information has arrived safely. This ensures your information hasn’t been tampered with while traveling to the receiver, and provides proof the information came from a verified sender. 

The additional security of asymmetric encryption means it can be slower than the symmetric method. This can affect performance, so it’s less suitable for encrypting large amounts of data.  

Asymmetric keys are generally much longer in length than symmetric keys. This means it takes more time to decrypt them and change your information from ciphertext to plaintext.

What Is AES Encryption?

You might’ve heard of AES encryption when exploring VPNs. It stands for Advanced Encryption Standard. AES is one of the most secure encryption protocols to use. VPNs use AES encryption to send your information through the secure VPN tunnel.

First, the VPN establishes a connection between your device and the VPN server using asymmetric encryption. This connection is the VPN tunnel. Then it uses symmetric encryption to pass your information through the tunnel. 

Rather than simply sending everything at once, AES encryption cuts your data up into small blocks known as data packets. Every packet is encrypted again, which is known as encapsulation. 

Every data packet also has its own key. Once a packet has arrived safely, the next one can be unlocked, and so on. This means if one block was tampered with, it wouldn’t affect all of your information, only the data in that one block.

AES encryption has different key sizes. The bigger the key, the more variations you need to guess to decrypt it. Most VPNs offer 256-bit AES encryption. 

This number refers to the size of the key and the number of variations needed to decrypt it. For this type of encryption, your data is broken in 256 separate packets, with a total of 2²⁵⁶ unique code combinations. As you’d expect, this is almost impossible to crack, which is why it’s one of the most advanced encryption methods available.

What is the Difference Between Symmetric and Asymmetric Encryption?

Symmetric Encryption	Asymmetric Encryption
Relies on a public key to encrypt and decrypt data.	Uses public and private keys to encrypt and decrypt data.
The key to encrypt and decrypt data is exactly the same.	The keys to encrypt and decrypt data are different.
Fast encryption and decryption process.	Slower encryption and decryption process.
Smaller key sizes with fewer decryption combinations.	Larger key sizes with more decryption combinations.
Used to secure large amounts of data at rest or for transfer.	Used to transfer small amounts of data.
Less complex to use as it only relies on a single key.	More complex to use as it relies on two keys.
No authentication, only confidentiality of data.	Includes data authentication alongside confidentiality of data.
Can be considered less secure as only one key is used.	Generally considered more secure as it relies on two separate keys.
Types include AES, Blowfish, and 3DES	Types include RSA and ECC

Both asymmetric or symmetric encryption are reliable solutions but are suited better to different use cases. 

For securing large amounts of data at rest or via transfer, symmetric encryption may be the better option. Its speed and efficiency allow you to send high volumes of data quickly. 

If you’re sending a highly confidential file and need an extra level of security, asymmetric encryption may be more suitable. The use of private keys provides an additional level of authentication, ensuring your file has arrived safely and hasn’t been tampered with. 

Using two separate keys (public and private) also helps to minimize the risk of an outsider accessing your data. It’s unlikely they’d know both the public and private key to decrypt the information. 

In most cases, symmetric encryption is best when speed, performance, and high volumes of data are concerned. Asymmetric encryption is more suited when extra security is required or to prevent unauthorized access to highly sensitive files.

Encryption: The Key to Data Security

Both asymmetric and symmetric encryption scramble your traffic, stopping snoopers from seeing your information. Which one you use comes down to whether you want speed or more security. 

Asymmetric encryption adds another layer of security with authentication and the use of private keys, making sure your data arrives safely. Symmetric encryption only uses a single public key, but it encrypts and decrypts your data at a higher speed.

For reliable encryption that keeps your information secure, you can download CyberGhost VPN. Our VPN scrambles your traffic not once, but twice. Everything you do while connected travels through the VPN tunnel, which is nearly impossible to break through. Keep your online searches and activities securely locked away.

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