The standard blackberry is encrypted between primary senders. The data is routed via the servers at Blackberry. The bigger question is if the OS10 devices follow the same path. If they do not route encrypted via Blackberry it may be less secure. One thing about security is the OS on any version so far is generally immune to any viruses or other intrusion other cell phones including the Apple and Androids are subject to.
The attached link offers more details. They do indicate the security path is the same for all BB's
http://btsc.webapps.blackberry.com/b...ListHelperImpl