No security options for external hard disk erase in Disk Utility I'm trying to erase an external disk drive that I had been using as a backup disk. There are no options for me to securely erase - the option just isn't there at all.

It is currently formatted as MAC OS Extended (Journaled, Encrypted).

I have a second HDD drive that when mounted shows the security options when erasing.

Any ideas what is going on here? This is a new problem for me; I'm sure I've secure erased this disk before.

Edit: I've just noticed that the only difference between the two disks is that the one that could be securely erased is down as a 'USB External Physical Volume' whereas the disk I'm having the problems with comes up as a 'CoreStorage logical volume'. Is this the issue?
MacOS doesn't let you do a Secure Erase on encrypted volumes because there's no point: a single erase will delete the encryption keys; and any residual data on the disk will be meaningless junk that cannot be decrypted.

Multiple zeroing of a mechanical disk can put significant stress on it and shorten its lifespan.

Similarly, MacOS doesn't let you secure erase SSDs, because that's also a pointless exercise: doing the erase doesn't actually make it more securely erased.

Why is a secure erase &#39;not necessary&#39; for SSD&#39;s?