data for Threshold Implementation of ACORN as well as for generating the CSTN configuration, and (4) a substitution box placed after CSTN to eliminate the linearity/predictability of the ciphertext. The overall architecture of *ExTru* has been demonstrated in Fig. \[extruarch\] for both transmitter side and receiver side.

On the transmitter side, the CSTN is used to permute/toggle the plaintext using the configuration (TRN) generated by the random number generator (RNG). The RNG will periodically change the configuration (TRN) to add dynamicity into the permutation/toggle network (CSTN). Parts of the configuration is fed by the permuted/toggled data (the output of the CSTN) to make the operation stateful (data-dependent). The CSTN is followed only by a substitution-box to eliminate the linearity/predictability of the output. The TRN that is used to configure the CSTN has been also encrypted using the authenticated cipher to be transmitted to the receiver. The key used for authenticated cipher could be pre-stored in the secure memory or produced by a PUF. The output of the transmitter (ciphertext) would be selected from the output of the s-box (permuted/toggled + substituted plaintext) or authenticated cipher output (encrypted TRN).

On the receiver side, on the other hand, the reverse CSTN (RCSTN) 