Certified - CompTIA IT Fundamentals+

In this episode, we explore the concept of encryption and how it protects data both when it is stored and when it is moving. Encryption is a core component of modern cybersecurity, and understanding how it works is essential for both everyday users and IT professionals. We’ll define what encryption is, explain the difference between data at rest and data in transit, and show how each form of data can be protected. This topic appears in Domain Six of the Information Technology Fundamentals Plus exam.
On the exam, you may encounter questions that describe a data scenario and ask you to identify whether encryption is protecting data at rest or in transit. You might also be asked to match encryption tools or protocols to their correct use case. The exam does not require any knowledge of cryptographic algorithms or configuration steps. Instead, your task is to understand when encryption is used, what it protects, and how it contributes to overall security.
Encryption is a process that transforms readable information into a coded format that cannot be understood without the proper key. This process is known as encrypting the data, and to view the original content, a user must decrypt it using the correct key. Encryption is one of the most reliable ways to protect sensitive information from unauthorized access, especially if a device is lost or data is intercepted during transfer.
Data at rest refers to information that is stored and not actively moving. This includes files saved on a computer, external hard drive, USB stick, or cloud server. Because this data is sitting in place, it may be accessed by anyone who gains physical or digital access to the device. To prevent unauthorized access, encryption tools can be applied to the entire storage drive or to specific files and folders. This ensures the data remains unreadable unless properly unlocked.
Data in transit is information actively moving between systems. It includes emails being sent, files being uploaded or downloaded, and messages being exchanged through online platforms. This type of data is particularly vulnerable to interception, especially on public networks or unsecured websites. To protect this data, encryption is used during the transfer process so that even if it’s intercepted, it cannot be read by unauthorized parties.
The difference between data at rest and data in transit is about whether the data is being stored or actively sent. When data is saved and not moving, it is at rest. When it is being transferred from one place to another, it is in transit. Both types are vulnerable and require different forms of encryption. The ITF Plus exam may describe a scenario involving a stored file or a secure website and ask which encryption type applies.
Examples of encryption at rest include encrypted hard drives on laptops, USB drives with password protection, and file-level encryption in cloud storage accounts. You may also encounter document files that are password protected using built-in features from office software. These examples ensure that stored data cannot be accessed if the device is lost or stolen. The encryption remains in place even if someone copies the data to another system.
Examples of encryption in transit include the HTTPS protocol used in web browsers, which protects data sent between your device and a website. Secure email services may encrypt messages between senders and recipients. Encrypted messaging apps use end-to-end encryption to ensure that only the sender and intended recipient can read the conversation. These tools are vital for maintaining privacy during data exchange, especially over public internet connections.
Encryption supports confidentiality by ensuring that only those with the correct decryption key can access the information. This is especially important for protecting personal data, financial records, and business communications. Even if encrypted data is stolen or intercepted, it remains unreadable without the proper credentials. This protection greatly reduces the impact of data breaches or physical theft.
One of the easiest ways to recognize encryption in transit is through your web browser. Websites that use HTTPS are encrypting traffic between your device and the site. Most browsers show a padlock icon in the address bar to indicate that the connection is secure. Clicking on this icon provides more details about the site’s certificate and encryption status. This was covered in more depth in Episode 86, but is important to review again in the context of encryption overall.
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Device-level encryption tools are commonly built into modern operating systems and provide protection for data at rest. Examples include BitLocker on Windows and FileVault on macOS. These tools can encrypt entire hard drives, ensuring that all stored files are unreadable without proper authentication. In some systems, device encryption is automatic, while in others, users or administrators must enable it manually. Regardless of setup, the goal is to prevent unauthorized access to stored information.
When transferring sensitive files over a network, secure file transfer protocols are essential. These include HTTPS for websites, FTPS for file transfers, and encrypted email attachments for secure communication. These protocols ensure that information moving between systems is encrypted during transmission. Without this protection, attackers could intercept unencrypted data, especially on public Wi-Fi or poorly secured networks. For the exam, remember that these tools represent encryption for data in transit.
While encryption is a powerful security tool, it is not a complete solution. Encryption does not prevent user mistakes, such as sharing a password or sending data to the wrong recipient. It also does not protect against malware that gains access after the data is decrypted. Encryption is most effective when used alongside other security measures like anti-malware software, firewalls, strong authentication, and secure browsing habits. It is one part of a larger defense strategy.
You may encounter exam questions that describe common scenarios and ask how encryption is applied. For example, “What protects a sensitive document stored on a laptop?” The correct answer would be encryption at rest. Or, “How is data sent securely from a browser to a website?” In this case, the correct answer would be encryption in transit, typically using HTTPS. Other questions might ask you to identify which method applies to email or cloud storage.
It’s also important to know what the ITF Plus exam does not include. You won’t be asked to explain how encryption algorithms work, generate keys, or manage digital certificates. There are no questions about specific encryption technologies like AES or RSA. The exam focuses on practical understanding—recognizing when encryption is used and what it protects—not on configuring or implementing cryptographic systems.
Encryption plays a central role in upholding confidentiality, the “C” in the C I A triad. When used correctly, it ensures that only authorized users can view or interact with protected data. Businesses use encryption to secure financial records, medical data, and proprietary information. Individuals rely on it to protect emails, cloud storage, and device contents. Encryption is a standard practice in nearly every digital system that handles sensitive or private data.
Both data at rest and data in transit require protection. Data at rest is vulnerable to physical theft or access through lost or stolen devices. Data in transit can be intercepted by attackers if sent over unencrypted networks. Together, these vulnerabilities highlight why both forms of encryption are necessary. A secure system encrypts stored data to prevent offline access and encrypts transmitted data to prevent online eavesdropping.
To recognize secure data handling practices, look for evidence of encryption. Use encrypted storage options for sensitive files, such as password-protected archives or encrypted drives. When sending information online, make sure the site uses HTTPS or that emails include secure attachments. When in doubt, ask whether the information is stored or moving—and then select the appropriate encryption method based on that status.
Encryption ties into many other security topics covered in Domain Six. It complements password protection by securing files even if a password is stolen. It supports secure browsing by protecting communications between users and websites. It also connects to safe software installation, cloud security, and access control practices. Understanding encryption strengthens your overall readiness for the exam and helps you think more broadly about how to protect data across all stages of its lifecycle.
To summarize, encryption is a method of protecting data by converting it into unreadable code. It is used to protect both data at rest—stored on a device—and data in transit—moving between systems. Encryption ensures confidentiality and limits the damage caused by theft or interception. The ITF Plus exam will test your understanding of these terms, use cases, and distinctions, but not on technical setup. Knowing when and how encryption is applied is essential for secure IT environments.