How to be sure
The solution would consist in calling the author of the proxy and ask him if it is still valid. This would assume that we know his phone number and that he answers.
The efficient solution is to have a proxy certified with CertiDox: a QR CODE is affixed to the document and its imprint is recorded in the CertiDox database.
unlike a website, there is no possible doubt about the origin of the CertiDox App:
The person who wishes to check the authenticity of the proxy can scan the QR CODE with the CertiDox App.
The reader flashes the QR CODE displayed on proxy with the CertiDox App that he has installed on his Smartphone / Tablet.
The CertiDox App indicates whether the QR CODE is present in its database.
If the answer is negative, the CertiDox App indicates that it is a fake.
If the answer is positive, the CertiDox App indicates
Note that proxies recorded in the CertiDox database are not accessible on the web to guarantee them total confidentiality: only flashing the QR CODE affixed to the document using a smartphone or tablet allows access to its content.
I wish to get further information about CertiDox to certify my proxies.
Next case study: authenticate a purchase order