AS many customer/clients would do for sensitive password or PIN details. You send part via email, part via text/SMS and part via verbal conversation = unless a monitoring, MalWare and camera exist at the destination hard to capture all three.. In the end - it really doesn't matter at all how preventative your methods at confidentially if the other person writes down your name, SS#, other information on a piece of paper and doesn't shred the paperwork (plus the next 5 sheets beneath it which may have an imprint) afterwards all your efforts are erased. In the end - if the individual fills out this information online via a public WIFI or uploads via non-secured connection all your efforts are erased. In the end - as Delta sent me a letter on April 11, 2018 of a security breach of their vendor [24]7.ai between Sept 26-OCt 12, 2017 (nice long delay) - so any efforts on your part are erased even if you and your friend both were diligent.

My response is not to discourage you or restrict your efforts, just recognize if you provide the details you should also have a credit freeze among all three credit bureau, and verify you require a pin when filling out your federal tax return. Just hope you are not a victim as you benefit from travel companion benefits.