A system comprising: a remote device for providing an operator interface for a user to configure and monitor a process; a controller configured to control the process; and a certificate authority (CA) configured to issue and to revoke certificates, wherein the controller is configured to use the certificates to mutually authenticate a user to enter into a secure mode of operation of the controller, in which the user is communicatively coupled with the controller, and in which the user is authorized to interact with the controller ; wherein the controller is configured to receive a request from the user to enter into the secure mode of operation and to validate a user certificate provided by the user; and if the user certificate is not valid, to alert of a first security violation; if the user certificate is valid, to request and validate a CA certificate from the CA; if the CA is not valid, to alert of a second security violation; if the CA certificate is valid, to request a new controller certificate from the CA and then to enter into the secure mode of operation, wherein in the secure mode operation the controller is configured to receive a user request for communication together with the user certificate , to validate the user certificate and, to alert of a security violation, if the user certificate is invalid, and to submit the controller certificate to the remote device , if the user certificate is valid, and wherein the remote device is configured to validate the controller certificate and to alert of a security violation, if the controller certificate is invalid, and to establish a secure connection, if the controller certificate is valid. a remote device for providing an operator interface for a user to configure and monitor a process; a controller configured to control the process; and a certificate authority (CA) configured to issue and to revoke certificates, wherein the controller is configured to use the certificates to mutually authenticate a user to enter into a secure mode of operation of the controller, in which the user is communicatively coupled with the controller, and in which the user is authorized to interact with the controller ; wherein the controller is configured to receive a request from the user to enter into the secure mode of operation and to validate a user certificate provided by the user; and if the user certificate is not valid, to alert of a first security violation; if the user certificate is valid, to request and validate a CA certificate from the CA; if the CA is not valid, to alert of a second security violation; if the CA certificate is valid, to request a new controller certificate from the CA and then to enter into the secure mode of operation, wherein in the secure mode operation the controller is configured to receive a user request for communication together with the user certificate , to validate the user certificate and, to alert of a security violation, if the user certificate is invalid, and to submit the controller certificate to the remote device , if the user certificate is valid, and wherein the remote device is configured to validate the controller certificate and to alert of a security violation, if the controller certificate is invalid, and to establish a secure connection, if the controller certificate is valid. <EOS>