Since NASes as usually 24/7 online, there is a certain risk of being hacked/compromised and it's not wise to rely solely on the drive's encryption inside of the NAS.

Is it possible to set up Time Machine to encrypt a backup on the MacBook and send encrypted data over to the NAS so that only by entering the passphrase on the MacBook can the backup be decrypted?

(I know this topic had been debated in the past but all threads are 5+ years old that's why I think it's worth reconsidering)

  • Not to sound contrary, but what leads you to believe the NAS encryption is not secure enough?
    – IconDaemon
    Nov 29, 2020 at 16:59
  • @IconDaemon Valid question. My answer is: because multiple users have access to the NAS (can install plug-ins, VMs) whereas only I have access to my MacBook. Therefore I find that encrypting with a passphrase on my Mac locally leads to a much lower chance of the passphrase being compromised (or the NAS being hacked due to a vulnerability in a plug-in). Nov 29, 2020 at 18:04
  • Maybe I'm just not getting what you are asking. Why isn't "Encrypt backups" good enough which you can select when setting up the network drive in Time Machine settings?
    – not2savvy
    Nov 29, 2020 at 22:21
  • @not2savvy That would be great! I read on this forum that this wasn't possible (and I can test it myself since I don't own a NAS yet). Are you sure that "Encrypt backups" work for network drives, as well and that the passphrase is not stored in the backup? Nov 30, 2020 at 5:16
  • 1
    I use it with network backups, and it works well. The passphrase is stored only locally in your keychain.
    – not2savvy
    Nov 30, 2020 at 6:06

1 Answer 1


If you select Encrypt backups when setting up Time Machine, the backup data will be encrypted using the encryption password you enter. The password is stored in your keychain to allow its use by Time Machine.

The backup data cannot be decrypted by anyone else unless they have the password.

To further increase safety, you may want to consider setting up different users on the network drive and let each user use their own storage for their backup data.

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