A wired communication system for transmitting security information over a wired link in addition to a payload, the wired communication system comprising a transmitter and a receiver coupled over the wired link, wherein the transmitter comprises: a first processor configured to: receive a first physical layer transmit frame comprising at least a first plurality of bits indicative of the payload and a second plurality of consecutive zero-bits, wherein the second plurality of zero-bits are defined by a communication standard to encode the payload using Low-Density-Parity-Check-Code, LDPC, encoding such that the payload is protected against transmission errors; and replace at least part of the second plurality of zero-bits with a third plurality of bits indicative of security information in order to generate a second physical layer transmit frame, and a first interface configured to output, based on the second physical layer transmit frame, one or more transmit signals to the wired link, and wherein the receiver comprises: a second interface configured to receive the one or more transmit signals from the wired link; and a second processor configured to: determine, based on the one or more transmit signals, a first physical layer receive frame comprising at least the first plurality of bits and the third plurality of bits, wherein the first physical layer receive frame is an LDPC frame; extract the third plurality of bits from the first physical layer receive frame; and replace the third plurality of bits with zero-bits in order to generate a second physical layer receive frame. wherein the transmitter comprises: a first processor configured to: receive a first physical layer transmit frame comprising at least a first plurality of bits indicative of the payload and a second plurality of consecutive zero-bits, wherein the second plurality of zero-bits are defined by a communication standard to encode the payload using Low-Density-Parity-Check-Code, LDPC, encoding such that the payload is protected against transmission errors; and replace at least part of the second plurality of zero-bits with a third plurality of bits indicative of security information in order to generate a second physical layer transmit frame, and a first interface configured to output, based on the second physical layer transmit frame, one or more transmit signals to the wired link, and a first processor configured to: receive a first physical layer transmit frame comprising at least a first plurality of bits indicative of the payload and a second plurality of consecutive zero-bits, wherein the second plurality of zero-bits are defined by a communication standard to encode the payload using Low-Density-Parity-Check-Code, LDPC, encoding such that the payload is protected against transmission errors; and replace at least part of the second plurality of zero-bits with a third plurality of bits indicative of security information in order to generate a second physical layer transmit frame, and receive a first physical layer transmit frame comprising at least a first plurality of bits indicative of the payload and a second plurality of consecutive zero-bits, wherein the second plurality of zero-bits are defined by a communication standard to encode the payload using Low-Density-Parity-Check-Code, LDPC, encoding such that the payload is protected against transmission errors; and replace at least part of the second plurality of zero-bits with a third plurality of bits indicative of security information in order to generate a second physical layer transmit frame, and a first interface configured to output, based on the second physical layer transmit frame, one or more transmit signals to the wired link, and wherein the receiver comprises: a second interface configured to receive the one or more transmit signals from the wired link; and a second processor configured to: determine, based on the one or more transmit signals, a first physical layer receive frame comprising at least the first plurality of bits and the third plurality of bits, wherein the first physical layer receive frame is an LDPC frame; extract the third plurality of bits from the first physical layer receive frame; and replace the third plurality of bits with zero-bits in order to generate a second physical layer receive frame. a second interface configured to receive the one or more transmit signals from the wired link; and a second processor configured to: determine, based on the one or more transmit signals, a first physical layer receive frame comprising at least the first plurality of bits and the third plurality of bits, wherein the first physical layer receive frame is an LDPC frame; extract the third plurality of bits from the first physical layer receive frame; and replace the third plurality of bits with zero-bits in order to generate a second physical layer receive frame. determine, based on the one or more transmit signals, a first physical layer receive frame comprising at least the first plurality of bits and the third plurality of bits, wherein the first physical layer receive frame is an LDPC frame; extract the third plurality of bits from the first physical layer receive frame; and replace the third plurality of bits with zero-bits in order to generate a second physical layer receive frame.