Preview.app Signatures - how to unencrypt without old keychain
Go to ~/Library/Keychains on your new Mac and make a copy/backup of your actual login.keychain with cmd D

Copy the old login.keychain in /Users/old_user_name/Library/Keychains from the backup to your desktop and rename it to loginold.keychain

Open Keychain Access.app and choose File -&gt; 'Add Keychain...' in the menu, navigate to your desktop and select loginold.keychain

Now you have a new entry in Keychains named loginold. Choose loginold in Keychains and Passwords in Category


Select the object Preview Signature Privacy and drag it to the keychain login in Keychains. You will be asked for a password. Enter the password for the old keychain (probably your old user password) and choose Always Allow or Allow. Now the object will be moved to your login keychain.

Choose login in Keychains and Passwords in Category and check if the new object Preview Signature Privacy is present there.

If everything is ok right click loginold in Keychains and choose Delete keychain &quot;loginold&quot;. If you choose Delete Files and References in the following dialog box the keychain loginold will be deleted from your desktop and in Keychains


Quit Keychain Access.app

Test everything with Preview.app

If everything went well go to ~/Library/Keychains and delete the file login copy.keychain built for safety reasons in step 1.

If something went wrong, you might revert to your previous keychain by deleting login.keychain in ~/Library/Keychains and renaming login copy.keychain to login.keychain. Then i usually log out and in again or restart my Mac to be save.


Slightly alternative way if the object Preview Signature Privacy is already present in your keychain login:
Perform the steps 1-4 from above
5. Locate the Preview Signature Privacy in loginold in Keychains and Passwords in Category and double click to edit.
6. Click the Show password checkbox and enter the old user password
7. Now the password used to encrypt the signature images is visible. Copy &amp; paste it into a text editor and save the file or paste it directly into the password field of Preview Signature Privacy in your keychain login.
Any by Preview.app previously signed/protected object on your new Mac might be inaccessible then though.
Continue with the steps 7-11 from above