Better to know for certain (up to confidence and security in the encryption/authentication and key management scheme(s)) than to have faith in the unknown proce

Better to know for certain (up to confidence and security in the encryption/authentication and key management scheme(s)) than to have faith in the unknown processes and systems of a third party. However, as always, it's all about designing, implementing, and operating a good engineering solution to whatever threat model you have and use.