Types of Encryption: What to Know About Symmetric vs Asymmetric Encryption


Symmetric vs asymmetric encryption. As if understanding the word “encryption” was not complicated enough, the various forms of encryption are now supposed to be known! Well, that’s just what the encryption and public key infrastructure (PKI) universe is like. If you keep digging deeper, you’ll be asked to explain more and more complex things. This may not appease our brain cells, but it is certainly a positive idea because it provides us with a better knowledge of a technology that safeguards our data and privacy.

We’ll take an in-depth look at the two forms of encryption at the core of modern-day web security in this article: symmetric encryption and asymmetric encryption. With some examples, we will also cover all encryption forms to help you better understand the content at hand.

But let’s briefly study a couple of the fundamentals first before we do that.

A Quick Recap: What is Encryption and Why Is It Necessary?

Encryption is the act of converting plaintext data into a scrambled format with the use of a cryptographic key such that no unauthorized party may see what the original data was. But that’s not only the advantage of using multiple forms of encryption, it can also help you protect the confidentiality of your files, applications, emails, and comply with certain laws and regulations on data protection and privacy.

Encryption is useful to encrypt a spectrum of personal identifying information (PII), financial information, intellectual property, and other confidential information, such as:

  • Names
  • Social security numbers
  • Contact information
  • Credit card information
  • Financial account information
  • Credentials
  • Technical specs, research, and other sensitive data

Encryption Keys Help to Secure Your Information

Regardless of the kind of encryption you’re looking at, a digital key would be needed. A cryptographic key, which is part of an encryption algorithm, is a series of randomly generated characters. If you equate the encryption method of locking your home’s entrance, then the encryption becomes the door lock system, and the encryption key becomes the physical key.

In terms of the use of keys, however, encryption varies from physical locks: In encryption, the same key that encrypted the data may or may not be used to decrypt it. This is an explanation of the contrast between symmetric and asymmetric encryption, the two forms of encryption that we will discuss in this post.

Breaking Down Encryption Forms and Examples: Symmetric vs Asymmetric Encryption

Symmetric Encryption

In basic terms, the easier and more conventional means of protecting data is symmetric encryption. The explanation why it is called “symmetric” is because it is a mechanism requiring the use of one key to encrypt and decrypt the data for all communicating parties.

An Example of Symmetric Encryption in Action

Let’s understand it with two of our favorite characters: Alice and Bob (after Homer and Bart Simpson).

Let’s say Bob is an undercover intelligence operative in a foreign country on a classified mission. In the other hand, Alice, who is tracking and directing him, is his case officer. Bob, who is surrounded by rivals, gathers information in order to give it to Alice. But he is highly worried: the data he sends to Alice could be captured by rivals, and he could be revealed.

To prevent that from happening, Alice gives Bob a hidden key and asks him before sending it to encrypt all the information. Bob agrees, and to encrypt the details, he uses this key. To access the hidden files, Alice has the same key and applies the same key to decrypt the data. This way, the identity of Bob remains a mystery, and the information is passed on to Alice, generating a win-win scenario.

Advantages & Disadvantages of Symmetric Encryption

When it comes to the symmetric encryption form, the most important value is its simplicity. Symmetric encryption algorithms are thought to be the fastest of the two forms of encryption since they have only one key doing encryption and decryption and need fewer computing power to do.

The simplicity of symmetric encryption algorithms, however, is not perfect; it has a problem known as “key distribution.” Symmetric encryption works just fine in Bob and Alice’s case, as there are only two entities: a sender and a receiver. But what if Alice receives information from thousands of different sources? If she gives all of her agents the same key, so any piece of data becomes insecure if the key is leaked somewhere. And if Alice sends everyone different symmetrical keys, that means she needs to carry thousands of keys, which isn’t a realistic thing to do.

When you extend this notion to the millions of everyday interactions between users (internet browsers) and web servers (websites), you can appreciate how impractical it can be on a wide scale.

Asymmetric Encryption

Asymmetric encryption requires the use of several keys for data encryption and decryption, which you might infer from its name. To be precise, two encryption keys that are mathematically connected to each other comprise the asymmetric encryption process. Such keys are known as the private key and the public key. As a consequence, the process of asymmetric encryption is also known as’ cryptography of the public key.’

An Example of Asymmetric Encryption in Action

Let’s explain this, with the example of Alice and Bob once again, as you correctly guessed.

Bob is an undercover spy agent who is on a covert mission in a foreign country and Alice is his case manager, as we stated earlier in the symmetric encryption example. Bob wants to transmit data in such a way that his rivals don’t decrypt or tamper with it. But Alice works out a new way to protect the data this time and she gives Bob one key, known as the public key.

Using the public key he has, Bob is told to encrypt his private details. In the other hand, Alice has a mathematically linked private key and can use it to quickly decode the data he transmits.

Advantages and Disadvantages of Asymmetric Encryption

The explanation why it was important to invent asymmetric encryption was to solve the issue of key distribution that occurs in the case of the symmetric encryption method. In the case of Bob and Alice, thus, even though the enemies have the public key of Bob, they won’t be able to decode the details because it can only be decrypted with the private key of Alice. Not just that, but the key management dilemma is also addressed by public key cryptography, even though Alice gets information from millions of sources. What she has to do is to lock the private key and handle it.

However, everything comes with a price, like other things in our world, and asymmetric encryption is no different. In this case, since this encryption algorithm requires longer keys, the price tag comes in the form of reduced speed and processing power. This is why asymmetric encryption is considered slower but more stable of the two forms of encryption.

Hybrid Encryption: Symmetric + Asymmetric Encryption

As we have shown, all encryption strategies have their own strengths as well as drawbacks. But, what if we build a framework that has the benefits of both? Yeah, surely it’s true. Symmetric and asymmetric encryption approaches are used together in many implementations, the most important of which is the security sockets layer (SSL)/transport layer security (TLS) cryptographic protocols.

First, the identity checking is performed using asymmetric encryption of SSL/TLS certificates. If the server’s identity has been checked, using ephemeral symmetric encryption keys, the encryption process occurs. In this way, symmetric encryption vulnerability risks and asymmetric encryption performance/speed problems can be mitigated. Cool, aren’t they?

Final Word on These Types of Encryption

Many individuals ask me to score which encryption approach is easier, symmetric than asymmetric encryption, after running over encryption forms and instances. Frankly, with my responses, I’ve never been able to impress people as they probably want me to say one or the other. If you speak solely from the security viewpoint, then yes, the best solution is undeniably asymmetric encryption. It’s not just about defense, though, as success matters as much, if not more so. It is where the image comes with symmetric encryption.

The thing is, all these forms and examples of encryption serve a purpose and are very important to our survival. Choosing one at the detriment of the other would be reckless. These two forms of encryption will remain as important as they are now, as long as we are concerned about data encryption.

Mark Funk
Mark Funk is an experienced information security specialist who works with enterprises to mature and improve their enterprise security programs. Previously, he worked as a security news reporter.