Like all nascent technology, the boom in the Internet of Things (IoT) over the last few years has presented a new set of security challenges. And given the small size and limited processing power of many IoT devices – encryption standards for the IoT can differ compared to many other device classes.
With this in mind, we’ve put together this guide to IoT data encryption. Below we explore the different types of encryptions and discuss the most common IoT encryption methods. Let’s get into it.
What Are the Main Types of IoT Data Encryption?
There are two main types of encryption in the IoT: symmetric and asymmetric.
The symmetric encryption method uses a singular cryptographic key to encrypt and decrypt the data received. As there’s a single key used for both operations, the process is relatively straightforward. This is the chief advantage of symmetric encryption. The simplicity of this encryption algorithm means it’s extremely fast, requires less power, and doesn’t affect Wi-Fi/internet speed.
Asymmetric encryption differs as it involves multiple keys for the encryption and decryption of data. There are two distinct keys that are mathematically linked to one another; the “public key” and the “private key.”
The advantage of asymmetric encryption is the enhanced level of security it provides. The public key is used to encrypt the data, while the decryption is done using the private key, which is stored securely. Another benefit is that asymmetric encryption is authenticated; the data can only be seen by the person or organization that’s meant to receive it.
The Most Common IoT Encryption Algorithms
Now we’ve outlined the two different types of encryption, let’s get into the most common encryption algorithms for the IoT.
Advanced Encryption Standard (AES)
The Advanced Encryption Standard (AES) is an IoT encryption algorithm that’s used by the US government’s National Security Agency (NSA) – as well as many other large organizations.
Since it was developed in 1997, the AES has become increasingly popular. This is due to its easy implementation in hardware and restricted environments. In fact, after it was declassified, this symmetric encryption algorithm was declared to be ‘capable of protecting sensitive government information well into the next century’.
AES is extremely efficient when used in 128-bit form. However, it also uses keys of 192 and 256 bits for heavy-duty encryption.
Within the security world, AES is highly thought of and considered to be resistant to cyber-attacks. It’s the world’s most widely used encryption algorithm – and can be found in these IoT applications:
- Wi-Fi security<
- Mobile app encryption
- Wireless security
- Processor security and file encryption
Data Encryption Standard (DES)
The Data Encryption Standard (DES) is one of the oldest encryption algorithms. In 1976, IBM introduced this symmetric encryption algorithm to protect sensitive and unclassified government data. It was adopted by federal agencies the following year.
Despite being considered the cornerstone of cryptography, the DES is no longer in use today. This is because it was cracked by many security researchers. As a result, it was replaced by AES.
DES fell down because of its low encryption key length, which made it susceptible to brute-force cryptographic hacks.
After the DES, came the Triple DES. This was designed to replace the original DES algorithm.
It uses three individual keys with 56-bits each. The total of the key length adds up to 168-bits. However, experts have disputed this and argued that 112-bits of key strength is more accurate.
>Much like its predecessor, the Triple-DES looks to be on its way out. It’s set to be gradually phased out as an IoT encryption method by 2023. However, it’s still considered a dependable encryption solution for payment systems, standards, and some other areas of fintech.
The RSA (Rivest–Shamir–Adleman) algorithm was developed way back in 1977. And it’s considered the most widely used asymmetric encryption algorithm. It allows users to send encrypted messages without having to previously share the code with the recipient. As a result, it’s extremely secure.
On top of its clear security benefits, the RSA algorithm is also incredibly scalable. It comes in various encryption key lengths, including:
- 4096-bit (and more)
As a result, even if shorter key-lengths are brute-forced, you can use encryption of higher key lengths to increase the difficulty of brute-force cryptographic hacks.
RSA encryption algorithms are used in many IoT applications. However, it’s most commonly found in SSL/TLS certifications, email encryption, and cryptocurrencies.
The DSA (Digital Signature Algorithm) is another asymmetric encryption algorithm. The DSA was first proposed by the National Institute of Standards and Technology (NIST) in 1991 and was then adopted by the Federal Information Processing Standard (FIPS) in 1993.
The DSA may be slower than the RSA for encryption and signing, but it’s faster at decryption and verification. That being said, as most are required for authentication, the two asymmetric algorithms kind of balance each other out.
The only key difference is that the DSA is endorsed by the U.S Federal Government. So, if an IoT product is providing services to a federal agency, the DSA enables it to comply with US government security protocols.
Blowfish is another symmetric encryption algorithm that was designed to replace DES. It splits messages into blocks of 64 bits and encrypts them individually.
A big reason for Blowfish’s ongoing popularity is that it’s freely available in the public domain. However, that doesn’t mean it’s not still a good encryption method. In fact, many claim it’s never been defeated.
Blowfish has been used to secure online payments and protect user passwords, among other things. It’s considered to be one of the most flexible and user-friendly encryption algorithms available.
Read Our Other Resources
We’ve published a range of IoT resources for our community, including:
- A Guide to IoT Protocols & Standards, which provides a complete overview of all the major protocols and standards available.
- The Top 10 Sensor Types in IoT and their Applications which provides an overview of the main sensors used in IoT.
- What is MQTT in IoT and Should You Use It?, which provides an overview of MQTT in IoT.
- MQTT Versus Websocket versus CoAP, which provides a comparison of three major protocols when applied to IoT.
- Our guide on how to Develop IoT Apps and what platforms you can use.