Since DevonThink does not provide encryption option, I save information that I need to be encrypted in PDF format, using Acrobat, using 128 bit AES.
What would be most convenient is to keep these encrypted PDF files in DevonThink, and when I click on these files, I should be prompted for the password, and then the content will become visible.
If this is not possible due to some limitation from Tiger, then the next best is to be able to specify which application is used to open encrypted PDF files. I don’t mind having to use Acrobat, but being able to keep the encrypted info in DT is more convenient than keeping it elsewhere. Of course, I don’t need search/classification/etc.
Simply Control-click (right click) on your encrypted file and choose Launch Path (if Acrobat is default for PDFs) or Open With and choose Acrobat. You will then be prompted by Acrobat to enter the password.
The fact that DEVONthink Pro’s Concordance knows every word in each document as well as the contextual patterns of those words presents interesting problems for the issue of encrypting individual documents. If the document can be opened and read in DT it can be indexed in DT. If indexed in ‘plain’ text it can be searched for, or show up in a similarity list in a See Also operation. I’m sure security regarding this will be managed in a future enterprise version, but not currently.
So it’s best to encrypt the entire database (I like an encrypted disk image to do that) or use the option you’ve described, such as encryption under Acrobat for individual documents.