Are willing to use plugins?
If so, you can use ScriptMaster to encrypt field data. Otherwise you would have to create your own encryption algorithm.
Another option would be using OpenSSL and Base Elements plugin so you can run it with terminal commands.
are you using FMP 13?
If yes, try this :
- define encrypted field as an auto-enter calculation field (text):
encrypted field = GetContainerAttribute ( salt_field & password_field; "MD5" )
- password_field is the field users type their password in
- salt_field is optional salt you may use.
I guess I should have mentioned that I need to be able to decrypt this field so that the user can see the information if they provide the correct password. Saving it as a hash won't allow me to do this will it?