Is Encrypting My Hard Drive Enough to Protect My Data Before Selling It?

From a security standpoint, encrypting the entire disk with BitLocker and then throwing away the key is a good approach. Just remember to ensure the whole disk is encrypted, not just the used space. However, for compliance reasons, this might not meet all standards. If you have a self-encrypting drive, you have other options too, like secure erase which effectively overwrites the old encryption key. Double-check what your compliance framework requires, and you'll be fine.

For compliance or when in doubt, just overwrite the data once with random patterns. One pass typically suffices because, physically, the old data gets masked by the new data. But if you're unsure about your specific situation, using a reliable tool like DBAN gives you extra peace of mind. It's easy, and you won't have to worry about any recovery than if you just toss the key.

Encrypting it and then junking the key is fine for personal use but may raise questions if it's part of a business sale. If you've written sensitive data originally, that might be risky. If it's strictly about making sure the next user can’t pull any of your old data, encrypting should do the trick, but maybe do a single wipe pass first just to be safe.

If you're really serious about sanitizing that drive, tools like DBAN or KillDisk can effectively ensure there's nothing left behind on a spinning drive. Just remember that DBAN is not suitable for SSDs but works perfectly for traditional HDDs. If you go the BitLocker route, just make sure the encryption has fully completed before disposing of the key.

Using BitLocker is practical, but keep in mind it's primarily approved for solid-state drives. With HDDs, you might be at risk of recovering data from bad sectors that aren't securely wiped. To be thorough, consider overwriting the drive once or even multiple times if you're feeling paranoid. The old data should be unrecoverable after that, especially if you later encrypt and erase the key.