This work presents the hardware demonstrator of a secure encryption system based on synchronised Chua chaotic circuits. In particular, the presented encryption system comprises two Chua circuits that are synchronised using a dedicated bidirectional synchronisation line. One of them forms part of the transmitter, while the other of the receiver. Both circuits are tuned to operate in a chaotic mode. The output (chaotic) signal of the first circuit (transmitter) is digitised and then combined with the message to be encrypted, through an XOR gate. The second Chua circuit (receiver) is used for the decryption; the output chaotic signal of this circuit is similarly digitised and combined with the encrypted message to retrieve the original message. Our hardware demonstrator proves that this method can be used in order to provide extremely lightweight real-world, chaos-based cryptographic solutions.