Abstract: An encryption retransmission device for providing resiliency against attacks. The encryption retransmission device includes an encryption unit, a communication unit, and a galvanic isolator. The encryption unit encrypts an egressing native packet and adds a connectionless header forms an egressing connectionless datagram, and decrypts an encrypted ingressing native packet of an ingressing connectionless datagram. The communication unit communicatively couples with the encryption unit, adds a complex header to the egressing connectionless datagram for forming an egressing packet for delivery to the first encryption retransmission device, receives an ingressing packet comprising the encrypted ingressing native packet and a complex header from the first encryption retransmission device, removes the complex header and adds a connectionless header for forming the ingressing connectionless datagram.