Quick Summary
Encrypting an external USB drive allows you to secure sensitive data stored on the drive. Common encryption methods for USB drives include BitLocker for Windows, FileVault for Mac, and third-party encryption software like VeraCrypt. To encrypt the drive, you’ll enable encryption in your operating system or with encryption software, select the external drive to encrypt, then set a password. Once encrypted, you’ll need to enter the password each time you connect the USB drive to access the data. Encryption protects the contents if the drive is lost or stolen.
What is an external USB drive encryption?
An external USB drive encryption refers to protecting and securing the data stored on a USB flash drive or external hard drive by scrambling it. Encrypted data looks like random gibberish to anyone who doesn’t have the decryption key or password. The data is encrypted and decrypted on the fly as it is written to or read from the encrypted drive.
Why should you encrypt an external drive?
Here are some key reasons to encrypt an external USB drive:
- Prevent unauthorized access – Encryption prevents others from accessing the data if the drive is lost or stolen
- Privacy and security – Encryption protects sensitive personal and business data from prying eyes
- Compliance – Encryption may be required to meet regulatory compliance standards like HIPAA for health data or PCI DSS for credit card data
- Corporate policies – Many organizations require encryption to protect intellectual property and customer data
- Safe disposal – Encryption allows safe disposal of old drives without worrying about data leaks
Overall, encryption provides an added layer of security and peace of mind for external drives that contain private or confidential data.
How does drive encryption work?
Encryption works by using an encryption algorithm and a key to scramble data into ciphertext that looks unreadable without the proper key to decipher it. Here is a basic overview:
- Encryption algorithm – This is a mathematical function that scrambles plaintext data into ciphertext based on an encryption key.
- Encryption key – This is a randomly generated string of bits created by the encryption algorithm. It is used by the algorithm to encrypt and decrypt the data.
- Ciphertext – This refers to the encrypted data that can only be returned to plaintext when decrypted with the proper encryption key.
- To encrypt: Algorithm + Key + Plaintext = Ciphertext
- To decrypt: Algorithm + Key + Ciphertext = Plaintext
The most common encryption algorithms used for drive encryption include AES (Advanced Encryption Standard) and Blowfish. The key ensures that only authorized users with the key can decrypt the ciphertext back into usable plaintext data.
How do I encrypt an external drive on Windows?
On Windows, you can use BitLocker drive encryption. Here’s how to set it up:
Requirements
- Windows 7 Ultimate or Enterprise, Windows 8 Pro or Enterprise, Windows 10 Pro, Enterprise, or Education
- An external drive that uses a compatible file system like NTFS, FAT32, or exFAT
- Administrator account access
Encryption Steps
- Connect the external USB drive to your Windows PC.
- Open Control Panel > System and Security > BitLocker Drive Encryption.
- Click “Turn on BitLocker” next to the drive letter of your external drive.
- Choose your encryption method:
- Used Disk Space Only encrypts used space (faster).
- New Encrypted Volume encrypts entire drive.
- Choose “Use a Password” to unlock the drive and enter a strong password.
- Save your encryption recovery key in case you forget the password.
- Click “Start Encrypting” to enable encryption.
- The encryption process may take a while depending on the drive size. Once complete, the drive will require the password to access.
Using the Encrypted Drive
After encryption, Windows will prompt you for the password each time you connect the drive. Enter the password to unlock and access the encrypted contents.
How do I encrypt an external drive on Mac?
On Mac, you can use FileVault full disk encryption. Here’s how to set it up:
Requirements
- Mac running macOS High Sierra 10.13 or later
- External drive formatted with Mac OS Extended or APFS file system
- Administrator account access
Encryption Steps
- Connect the external drive to your Mac.
- Open System Preferences > Security & Privacy > FileVault.
- Click “Turn on FileVault…”.
- Choose either “Store decryption key in iCloud” or “Store decryption key on a USB thumb drive” for the recovery key.
- Select the external drive and click “Encrypt”.
- Enter account password when prompted to start encryption.
- Encryption may take several hours depending on drive size. The drive will be unavailable until completed.
- Once encrypted, macOS will prompt for your password each time you connect the drive.
Using the Encrypted Drive
After encryption finishes, macOS will automatically decrypt the drive when you connect it and enter your password. You can access the files normally after unlocking the drive.
How do I encrypt an external drive using VeraCrypt?
VeraCrypt is a popular free and open source disk encryption tool. It works across Windows, Mac, and Linux. Here’s how to use it:
Requirements
- Download and install VeraCrypt on your device
- External drive with a compatible file system like NTFS or exFAT
- Administrator or root access to encrypt system drive partitions
Encryption Steps
- Launch VeraCrypt and select “Create Volume”
- Choose “Encrypt a non-system partition/drive” and click Next.
- Select the external drive partition or drive letter to encrypt.
- Choose volume type – Normal or Hidden. Hidden volumes provide plausible deniability.
- Select encryption algorithm (AES recommended) and hash algorithm (SHA-256).
- Enter a strong password.
- Choose volume format – dynamic or standard.
- Click “Encrypt” to start encryption process.
- Encrypted volume will mount as new drive letter/mount point once completed.
Using the Encrypted Drive
To access the VeraCrypt volume, open VeraCrypt, select the volume, enter your password, then click “Mount”. VeraCrypt will mount the volume as a new drive letter. Access files as normal after you unlock it.
How strong should my encryption password be?
For optimal security, your encryption password should be:
- At least 12-16 characters long
- Include a mix of lowercase, uppercase, numbers, and symbols
- Avoid common words, phrases, or patterns
- Not reused from other accounts or passwords
You may also consider enabling multi-factor authentication for additional security when unlocking encrypted volumes, if supported by your encryption platform.
A strong, unique password makes it extremely difficult for unauthorized people to gain access and decrypt your sensitive data if the drive is lost or stolen.
How much will encrypting an external drive reduce performance?
Encrypting an external USB drive does introduce a small performance penalty – extra processing is required to encrypt and decrypt data on the fly as it is written or read. However, with modern processors the impact is usually not noticeable for the typical user.
Some estimates on performance impact:
- Read/write speeds may be reduced by around 3-15% for many encryption algorithms.
- More intensive algorithms like AES tend to have higher overhead than lighter ones like Blowfish.
- Hardware-accelerated encryption can minimize performance impact.
- The encryption overhead is more noticeable on older, slower machines.
So in short – some minor reduction in speed is expected but encryption is still feasible for most external drives. The security benefits outweigh the small performance hit.
Can I encrypt a bootable external OS drive?
Most encryption solutions do allow you to encrypt external USB drives containing bootable operating systems, though the process may differ.
For Windows:
– BitLocker can perform full drive encryption on external Windows drives
– Use “Used Disk Space Only” encryption for best performance
For Mac:
– FileVault full disk encryption works on external Mac boot drives
– But you cannot use Mac’s native Boot Camp on encrypted volumes
For Linux:
– VeraCrypt and other tools allow encrypting external Linux OS drives
– May require pre-boot authentication to decrypt drive at startup
So encrypting a bootable external OS drive is definitely possible, but requires some care to ensure the drive is still bootable after encryption. The operating system needs to include drivers to read the encrypted drive before booting.
What risks are there with encryption?
While drive encryption provides greater security and privacy, some risks to be aware of include:
- Forgotten passwords – If you forget the password or lose encryption keys, the data will be inaccessible.
- Corrupted data – Errors during encryption/decryption process can corrupt data.
- Performance impact – Encryption introduces computational overhead that may reduce speed.
- Encryption failure – Buggy software, power loss, sudden failure during encryption, etc. can cause issues.
- Loss of drive – The encrypted drive itself could still be lost or damaged.
- Unauthorized access – Brute force attacks may be able to crack weak passwords.
Proper precautions can mitigate these risks, such as using strong passwords, storing a backup of encryption keys, preventing sudden power loss during encryption, and maintaining data backups separately from the encrypted drive.
Conclusion
Encrypting an external USB drive helps keep your data private and secure by scrambling it into unreadable ciphertext. Windows BitLocker, Mac FileVault, VeraCrypt, and other encryption tools make it straightforward to encrypt external storage devices. With an encrypted drive, you can securely take sensitive data with you without worrying about unauthorized access if the drive is ever misplaced. Just make sure to use a strong password and keep backups of encryption keys. With the proper precautions, encryption provides reliable protection for your external drive data.