Data at Rest Encryption: Protecting Stored Data

Securing sensitive information is more critical than ever. One of the key defenses in data protection is data at rest encryption, a method that safeguards information stored on devices such as hard drives, databases, and servers. Unlike data in transit, which is actively moving through networks, data at rest is idle, yet just as vulnerable to breaches. From personal devices to enterprise storage systems, encryption ensures that even if unauthorized access occurs, the data remains unreadable without the appropriate decryption keys. 

An alarming 53% of companies left more than 1,000 sensitive files and folders unencrypted, accessible to all employees. This article explores the various methods of encrypting data at rest, helping you understand the strengths and limitations of each approach to better protect your stored information.

What Is Data at Rest Encryption?

Data at rest refers to all the information that is stored on devices like hard drives, databases, or cloud storage when it is not actively being transmitted or processed. It’s the data that stays put — your files, emails, backups, and other information that is stored on servers or personal devices.

Now, just think about this data being leaked into the wrong hands. That's where data at rest encryption comes into play: Encryption encrypts this type of information by translating it to indecipherable code, meaning the only person who can read that encrypted file is someone with the right decryption key. In short, encryption helps protect your data from being read by anyone that does not have the key to unlock it.

Symmetric Encryption

Symmetric encryption is one of the most frequent and efficient methods to secure your stored data. Basically, the same key is used to encode in addition to decode information. Imagine you have a locked box — this box can only be opened with one key and both you and the recipient of your data use the same key. Symmetric encryption: The same key is used on both sides of the process.

Some common algorithms you will probably discover are AES (Advanced Encryption Standard) and DES (Data Encryption Standard). AES is very secure and typically used for data at rest encryption, while DES meanwhile considered obsolete supports the understanding of encryption techniques from earlier.

Asymmetric Encryption

Asymmetric encryption is one of the most secure methods you can use to store your data. Symmetric encryption uses a key to encrypt and decrypt your data, however, the asymmetric technique use two keys. One is public and can be shared with everyone, and the second is private and available only on the machine where it was generated. This type of method is extremely secure, as the associated keys are mathematically connected but still totally different.

In symmetric encryption, the same key is used on both ends. In asymmetric encryption (with public and private keys), only one person has that particular private key information. This is why it has been invaluable in data at rest encryption — safeguarding that sensitive data to the extent possible.

Typical uses for public key encryption include secure browser communications, email with end-to-end privacy and digital signatures to prove the source or integrity of a file. The best thing about using this feature is its security, as with end-to-end encryption you will never have to share your decryption keys that could possibly be intercepted.

Hybrid Encryption

Hybrid encryption combines the best of two worlds — symmetric and asymmetric encryption. You may already know that symmetric encryption uses one key to both encrypt and decrypt data, while asymmetric encryption uses a pair of keys (public and private) to do the same. In contrast, hybrid encryption combines the best of these two methods to allow a compromise between speed and security.

It goes like this: the bulk data is encrypted with a symmetric key since it can also be done faster. Then this symmetric key is again encrypted using asymmetric encryption, proving that only the target recipient with the correct private key can decrypt it. It is suitable for in-use encryption, which ensures a fast and secure exchange of keys as well as efficient processing of large datasets.

Hybrid encryption is used in many real-world applications, including securing file transfers, email communication and even cloud storage. An example of this is how your data remains encrypted even when it is uploaded to the cloud and then stored or sent over using a service. It keeps your cloud files secure from unauthorized access when the cloud services provider is compromised.

The benefits that hybrid encryption brings are obvious. You have the speed and performance of symmetric encryption + secure key management as with asymmetric. It is with this harmony in mind that hybrid encryption presents itself as a wise choice for data at rest security, securing your critical information all the while ensuring efficiency.

File-Level Encryption

Full-disk encryption (FDE) is a powerful security measure that protects your entire hard drive. By encrypting every bit of data on your disk, FDE ensures that unauthorized users cannot access your files. Whether you’re using a laptop, desktop, or external drive, this encryption method guards your data at rest by scrambling it into unreadable code, which only authorized users can decode.

Popular Tools and Methods

Several tools can help you implement full-disk encryption:

• BitLocker: A built-in encryption tool for Windows users, BitLocker encrypts your entire drive and integrates seamlessly with the operating system.
• FileVault: Available for macOS, FileVault provides robust encryption for your Mac’s disk, ensuring your data remains secure.
• VeraCrypt: An open-source alternative that offers cross-platform support, VeraCrypt provides strong encryption options for various operating systems.

Pros

• Enhanced Security: Full-disk encryption safeguards all your data at rest, protecting it from unauthorized access even if your device is lost or stolen.
• Ease of Use: Once set up, it runs in the background with minimal impact on your daily activities.

Cons

• Performance Impact: Encryption can slow down your system slightly, as it requires additional processing power to encrypt and decrypt data.
• Complex Recovery: In case of hardware failure or forgotten passwords, recovering encrypted data can be challenging.

Database Encryption

By encrypting sensitive data, you’re adding a protective layer to your databases. This is especially critical when it comes to personally identifiable information (PII), financial data, and other sensitive details. Encryption encrypts the data meaning your files are scrambled until unscrambled by using the keys, making your data secure at rest and in transit. When multiple updates are done through the CI/CD pipeline, encryption works effortlessly to make certain that every deployment delivers optimum security.

Challenges and Best Practices

On the other hand, database encryption poses different difficulties. However, things can become quite complex when managing encryption keys, balancing performance and security tradeoffs, and ensuring compliance with internal policies or industry standards for data protection. The best way to overcome these challenges is:

• Use solid key management systems: Use powerful and safe key management structures to save your encryption keys.
• Embed encryption in your CI/CD pipeline: Keep it a part of the development and deployment so that no one gets to play with data in continuous integration/deployment cycles.
• Regular reviews: Regularly evaluate how you encrypt and ensure it meets the current security standards.

Full-Disk Encryption

Full-disk encryption is a security approach designed to encrypt the data on your hard drive, protecting every byte of information. FDE acts as armor for both personal photos and sensitive work files, rendering the drive’s contents unreadable to anyone without the proper decryption key. This is one of the most efficient forms of data at rest encryption, as it literally puts a layer of protection around your entire drive.

You likely heard about the most popular tools for full-disk encryption, such as BitLocker and FileVault. Windows frequently employs BitLocker, which is tied to your user login by strong encryption. Mac systems also use a similar tool known as FileVault. Both are simple to use and enable you to seal off your entire drive in a matter of clicks.

While full-disk encryption is highly secure, it does have its advantages and disadvantages. The main benefit is that it is very complete: you do not need to worry about encrypting individual files and folders.

Additionally, practically all modern operating systems come with FDE tools already installed and ready to use. Performance might be affected marginally, especially if you have an older system. If you forget your encryption password or lose your recovery key, your data is likely lost forever.

Overall, full-disk encryption provides a powerful layer of protection for your stored data, making it one of the best choices for data at rest encryption. Much like how blockchain technology secures data through decentralized encryption methods, full-disk encryption ensures that your entire drive is locked down, safeguarding your information against unauthorized access.

Choosing the Right Encryption Method

When selecting an encryption method for your data at rest, there are a few crucial factors to keep in mind: risk assessment, performance, and regulatory compliance.

• Risk Assessment: Start by evaluating the sensitivity of the data you’re protecting. Are you storing highly sensitive information, such as financial records or personal identifiers? The more valuable the data, the stronger encryption you’ll need. Symmetric encryption, like AES, is often a good choice due to its speed and security for sensitive information. On the other hand, if you’re securing less critical data, you may opt for file-level encryption, which provides flexibility.
• Performance: Encryption matters on the performance side as well. With that kind of strength comes great protection, but it could potentially slow your systems down. Full-disk encryption can slow down system performance, as it needs to encrypt everything on your device, but file-level encryption might offer a more optimal solution depending on which files you are looking to secure. Remember to find a sweet spot between security and speed, you do not want your systems slowed down for no reason.
• Regulatory Compliance: Take into account regulatory requirements. For example in the healthcare or finance industry, organizations are required to comply with HIPAA and GDPR laws which specifically require you to have certain encryption standards. This means that you must use encryption technology that adheres to these legal requirements in order not only to avoid fines but also to make sure your data is still officially compliant. Also, it is a good idea to use one of the best password managers to secure access to encrypted data, ensuring passwords themselves are protected.

Conclusion

Exploring different methods of data at rest encryption helps you understand how to effectively secure stored information. Whether you choose symmetric, asymmetric, or hybrid encryption, each method offers its own benefits based on your specific needs. File-level, full-disk, and database encryption provide further layers of protection, ensuring that sensitive data remains safe from unauthorized access. By selecting the right encryption method, you can better protect your data at rest and enhance your overall security.