Earlier quoted context omitted.
Provable identity: you get an email, hi i'm a hiring manager from company X, can we get in touch about job Y, could you please send me your (secret) phone number? It should be possible for you, the receiver of the email, to check if the email originated at company X. Digital Notary: this came up in several data privacy discussions. You (A) are in contact with B, but you don't want to send B something like a scan of y…
> It should be possible for you, the receiver of the email, to check if the email originated at company X. You could check the DKIM signature of the email.
The point being that Company X does not have a copy of the sensitive information (and neither the liability of losing it) and the Digital Notary would (in theory) have better procedures for properly deleting or storing the data as needed.