Unfortunately not. You can lock a layer but not password protect it.
As stated, no way to do exactly what you want, but an option might be to turn OFF Visibility for that Layer, if you do not want it seen, and then Flatten, and do a Save_As.
If you do want that Layer seen, but not able to be edited, then Flatten, with Visibility ON, and Save_As.
- The question is, do you want the recipient to see that Layer, or not?
- Next, Do they need to be able to edit all other Layers, but just not that one?
- Last, what type of Layer is it?
Locking a layer does not protect it from being gobbled up in a merge visible or flatten operation adding password protection why?