All e-mails sent by P&TS contain an S/Mime-type electronic signature, which allows the recipient to check that we are in fact the sender of this message. This signature removes almost all risk of phishing, that is opportunities for a third-party to usurp our e-mail address and to pass themselves off as P&TS, for example to obtain confidential information regarding a development or an invention.
However this signature can also be used in order to send us messages which only we can read. In order to do this, you need to import the public key contained in the signature, and use it to encrypt messages with the S/Mime functions included in all modern client messaging services. Since we have the private key corresponding to this public data encryption key, we can decode these messages.
The procedure even works on I-Phone. All you have to do is send an e-mail with the S/MIME certificate that you have imported on to your computer and install it. Then to encrypt messages, follow the instructions described in the following link : https://support.apple.com/en-us/HT202345.