What is a difference between symmetric and asymmetric encryption algorithms

But how do the server and browser on each end of the connection have the correct key for encrypting and decrypting data? The answer to that question is actually the main difference between symmetric and asymmetric encryption. First, let’s take a look at how symmetric encryption works. 

Defining symmetric encryption

In symmetric encryption, data is encrypted and decrypted by the same secret key that is shared by the recipient and the sender. This means that the key needs to be shared with the recipient in a secure way so that they and nobody else has access to it. It’s a high-speed method of encryption.

Defining asymmetric encryption

A more complicated process, asymmetric encryption works by using two different but mathematically related keys, the public key and the private key, to encrypt and decrypt data. The public key, which anyone can access, is used to encrypt the data. Only the complementary private key can be used to decrypt the message. 

Symmetric vs. Asymmetric encryption — the key differences

While symmetric encryption uses a single shared key to encrypt and decrypt data, asymmetric uses two separate keys. Symmetric encryption uses shorter keys (usually 128 or 256 bits). In comparison, asymmetric keys are a lot longer (sometimes 2048 bits or longer). This is why asymmetric encryption takes a little bit longer than symmetric. 

However, although symmetric encryption is a faster, more straightforward process, it’s more vulnerable to security risks due to the nature of keeping the shared key a secret. Meanwhile, asymmetric encryption may be a more complex and resultantly slower process, but it’s ultimately a far more secure encryption method. Unlike symmetric encryption, it can authenticate identities, which makes it ideal for messages sent between two parties previously unknown to each other (for example, a user visiting a website for the first time). 

On the other hand, symmetric encryption tends to mostly be used in internal IT security environments, where the secret key can be shared safely and securely between recipient and sender. 

TLS 1.3 and working in tandem

By now, you probably have a better idea of the differences between symmetric and asymmetric encryption and what kind of environments each is best suited to. But when it comes to SSL certificates, you don’t need to choose between the two. This is because TLS 1.3 — the current cryptographic protocol that underpins how SSLs work — uses a combination of both symmetric and asymmetric encryption. How exactly does that work?

For a user visiting a HTTPS website for the first time, the initial connection is made using asymmetric encryption. During the SSL handshake, the website server sends the client (the user’s browser) its public key. The client authenticates the public key, then uses it to create what’s known as a pre-master secret key. It encrypts this key with the public key and sends it back to the server. The server will then decrypt the pre-master secret key using the related private key. This pre-master secret key will be used to encrypt communications between the client and the server from this point forward, switching from asymmetric encryption to symmetric encryption.

By using this hybrid encryption system, TLS 1.3 has both the security benefits of asymmetric encryption with all the speed of symmetric encryption. 

Wrap up

Hopefully, you leave this article with a better understanding of the differences between symmetric and asymmetric encryption, as well as their strengths and weaknesses. While both types of encryption have pros and cons, they are equally important in their own right, particularly when used in combination with each other. 
If you want to secure your site with an SSL certificate, why not explore the range of affordable options SSLs.com has to offer. 

Cora Quigley

Cora is a digital copywriter for SSLs.com. Having eight years of experience in online content creation, she is a versatile writer with an interest in a wide variety of topics, ranging from technology to marketing.

In this article, we are going to discuss the difference between the types of encryption that are symmetric encryption and asymmetric encryption. It is very important to know about both terms and their difference.

Before discussing symmetric and asymmetric encryption, first, see a brief description of encryption.

What is encryption?

Encryption means that the sender converts original information into another form and sends the unintelligible message over the network. It helps us to secure data that we send, receives, and store. Data can be text messages saved on our cell phone, logs stored on our fitness watch, and details of banking sent by your online account.

It is the procedure of taking ordinary text, such as a text or email, and transforming it into an unreadable type of format known as "cipher text." The ciphertext is converted back to the real form when the recipient accesses the message, which is known as decryption. It helps to protect the digital information either saved on or spread through a network such as an internet on computer systems.

Symmetric encryption encrypts and decrypts the information using a single password. In this encryption technique, the message is encrypted with a key, and the same key is used for decrypting the message. It is the simplest and commonly known encryption technique. It makes it easy to use but less secure.

It is called symmetric encryption because the same key is responsible for encrypting or decrypting the data. The single key used in symmetric encryption is used to encrypt plain text into ciphertext, and that same key is used to decrypt that ciphertext back into plain text.

Symmetric encryption is also called secret key encryption. The algorithm behind the symmetric encryption executes faster and less complex, so it is the preferred technique to transmit the data in bulk.

Asymmetric encryption uses two keys for encryption and decryption. It is based on the technique of public and private keys. A public key, which is interchanged between more than one user. Data is decrypted by a private key, which is not exchanged. It is slower but more secure. The public key used in this encryption technique is available to everyone, but the private key used in it is not disclosed.

The drawback of this encryption is that it takes more time than the symmetric encryption process. Asymmetric encryption is slower than secret-key encryption because, in secret key encryption, a single shared key is used to encrypt and decrypt the message, while in public-key encryption, two different keys are used, both related to each other by a complex mathematical process. Therefore, we can say that encryption and decryption take more time in public-key encryption.

In asymmetric encryption, a message that is encrypted using a public key can be decrypted by a private key, while if the message is encrypted by a private key can be decrypted by using the public key. Asymmetric encryption is widely used in day-to-day communication channels, especially on the internet.

That's about the description of both encryption techniques. Both encryption techniques have their own benefits and limitations, but from a security perspective, asymmetric encryption is a better choice. Now, let's see the comparison chart between both techniques. We are comparing asymmetric and symmetric encryption based on some characteristics.