6.6 Explain common uses of encryption.
📘CompTIA ITF+ (FC0-U61)
- File-Level Encryption
Definition: Encrypts individual files or folders.
How it works: Each file is encrypted separately, so you can protect sensitive files without encrypting the whole system.
Example in IT environment:
A system administrator encrypts a confidential Excel spreadsheet containing employee salaries using AES encryption.
Even if the file is copied from the server to another device, it remains unreadable without the decryption key.
Benefit: Flexible and allows encryption only on specific files that are sensitive.
- Disk-Level Encryption
Definition: Encrypts the entire storage drive, including the operating system, applications, and all files.
How it works: The encryption happens automatically when data is written to the disk and decrypted automatically when read with proper credentials.
Example in IT environment:
A company uses BitLocker on Windows laptops.
If a laptop is stolen, the thief cannot access any data because the entire disk is encrypted.
Benefit: Strong protection for all data, ensures nothing is left unencrypted.
- Mobile Device Encryption
Definition: Encrypts data stored on smartphones and tablets.
How it works: Most modern mobile devices offer built-in encryption that protects emails, documents, and photos.
Example in IT environment:
A company issues iPhones to employees with device encryption enabled.
If a phone is lost, attackers cannot read corporate emails or stored files without the device password or biometric unlock.
Benefit: Essential for mobile security, especially when employees carry sensitive information.
Plain Text vs. Cipher Text
Understanding these concepts is key for exams.
- Plain Text
Definition: Data in its original, readable form. Anyone who accesses it can understand it.
Example in IT environment:
A password stored in a simple Excel file as P@ssw0rd is in plain text.
If the file is accessed by an unauthorized person, the password is fully visible.
- Cipher Text
Definition: Data that has been encrypted and is unreadable without a decryption key.
How it works: Encryption algorithms scramble the plain text into cipher text.
Example in IT environment:
The same password P@ssw0rd encrypted using AES might look like 3f7b9a1c8e2d….
Without the decryption key, no one can understand or use the password.
Key Takeaway for Exams:
Plain text = readable, vulnerable.
Cipher text = encrypted, protected.
Data at rest should always be encrypted to prevent unauthorized access.
Summary Table
Concept What it Protects IT Example Key Point
File-Level Encryption Individual files Confidential spreadsheet Flexible, protects only sensitive files
Disk-Level Encryption Entire disk BitLocker on laptops Strong protection, encrypts everything
Mobile Device Encryption Data on phones/tablets iPhone corporate device encryption Essential for mobile security
Plain Text Original readable data Password in Excel Vulnerable to theft or leaks
Cipher Text Encrypted data AES-encrypted password Secure, unreadable without key
💡 Exam Tip: In CompTIA ITF+, you may be asked to identify the difference between plain text and cipher text, or choose the right encryption method for a scenario (like encrypting a server, a single file, or a mobile device). Always remember: plain text is readable, cipher text is not.
