Does encrypting and de-crypting a drive affect HDD/SSD longevity?

Question

I have a Bitlocker-protected SSD that I am now using as a backup drive. I don't want to unlock it everytime I boot it up, so I decided to simply remove the password, but leave the drive encrypted so that I could quickly "re-activate" the encryption if I needed to.

I've since discovered that removing the password seems to equal de-crypting the drive. So I am hesitating because I worry that de-crypting and re-encrypting the drive repeatedly would somehow be detrimental to the hardware. But this is beyond my understanding of encryption* hence the question.

Is there a risk in de-crypting and re-encrypting data/partitions/drives?

_{*Intuitively, I didn't even think that the definition of encrypting something has to include a password. I mean I get that without a password, the data would be accessible- but wouldn't it still be encrypted?}

Answer 1

Does encrypting and de-crypting a drive affect HDD/SSD longevity?

Yes, but only in the same way as regular reading/writing. The encryption (or decryption) process has to read every sector on the disk, then write it back – this will add to an SSD's regular write count. The process does not involve any special operations besides that.

(I don't know whether BitLocker covers free space too, or whether it only encrypts 'in use' areas. The former is more secure; the latter is more SSD-friendly.)

I've since discovered that removing the password seems to equal de-crypting the drive

Intuitively, I didn't even think that the definition of encrypting something has to include a password. I mean I get that without a password, the data would be accessible- but wouldn't it still be encrypted?

Well, you're right that encryption does not require a "password"; but it still needs a key to be provided somehow. That key could be derived from a password you input to unlock; it could be stored in a TPM chip or a USB token; and yes, BitLocker actually does have a "suspend" command, where the drive is encrypted and its decryption key is stored on the drive itself.

So if you want to temporarily deactivate BitLocker, sure, you can do that – just not via the graphical interface; it's hidden behind a command-line tool. (The "suspend" feature is there mostly for the purpose of Windows Update and TPM. It should be obvious that it completely removes the security while suspended, but perhaps the UI designers wanted to avoid this risk.)

I decided to simply remove the password, but leave the drive encrypted so that I could quickly "re-activate" the encryption if I needed to.

The main problem with that is, whenever you need to quickly re-activate the encryption, it's usually too late. You can't predict that the drive will be stolen tomorrow.