Code Signing - PaddleHQ/Mac-Framework GitHub Wiki
Overview
The Paddle framework is not currently code signed. However, even if this were the case, your app and all included frameworks should be code signed with your developer identity.
Why?
Since OS X Mountain Lion, by default, GateKeeper is enabled to only run code signed apps. This is a security setting of OS X, which makes sure any apps running on the system have not been modified after they have been built.
What happens if my app isn't code signed properly?
Depending on system settings, any number of problems could be encountered. Ultimately, it could result in your users not being able to run your app.
Code Signing Process
After following the Paddle framework setup documentation, you should have already created a Copy Files Build Phase. You now need to create a Run Script Build Phase, which can be found under Editor->Add Build Phase->Add Run Script Build Phase.
Once you've done this, you should have a new Run Script Build Phase just after your Copy Files Build Phase.

In the script field, paste in the following, making sure to include your actual developer id:
LOCATION="${BUILT_PRODUCTS_DIR}"/"${FRAMEWORKS_FOLDER_PATH}"
IDENTITY="Developer ID Application: YOUR DEVELOPER ID"
codesign --verbose --force --sign "$IDENTITY" "$LOCATION/Paddle.framework/Versions/A"
Before building, ensure that signing with your Developer ID (or appropriate ID for MAS or non-MAS apps) and that the correct Team is selected. These options can be found under General after selecting your Target.

Build your app as usual and the Paddle framework will now be code signed along with the rest of your app.