Yes, we support SSL encryption, you just need to use https://... instead of http:// in all cals. This way you make sure all images and recognition results travel encrypted via network.
After recognition is done, you should call deleteTask method explicitly to remove recognition results and all copies of image, including cache. If you want to keep your images confidential, you have to delete them within 24 hours after task submission or completion. If you chose not doing so, you permit us to use these images for improving quality of service, but we still will respect yout data privacy.
More about that here: http://forum.ocrsdk.com/questions/479/privacy-plicy