# DNA-PRESENT: An Improved Security and Low-Latency, Lightweight Cryptographic Solution for IoT
## 5 Differential Cryptanalysis of DNA-PRESENT  
Differential cryptanalysis, introduced by [PERSON] and [PERSON] [80], is one of the most effective techniques for assessing the security strength of a cipher. It is a chosen plaintext-ciphertext attack, where the attacker can observe the encrypted output after selecting specific plaintexts as inputs to the cipher. To perform differential cryptanalysis, the attacker uses a pair of plaintexts that differ by a constant value. A differential path or trail represents a sequence of differences across multiple rounds of encryption. These paths are primarily established for the cipher's nonlinear component, which, in the PRESENT block cipher, is the s-box. While finding a differential path, there are multiple output differences against a particular input difference for s-box. Therefore, a difference distribution table of the s-box serves as a starting point for attackers, giving a certain output probability over input, as presented in [81]. The differential paths were only found until round 8, as shown in Table 12, and the cipher is secured for the full number of rounds. The maximum probability of difference propagation is observed at the 8 th round of \(2^{-79}\), lower than \(2^{-63}\), and presented in detail for each round from round 1 to round 8. As a result, it becomes impossible to build a successful differential distinguisher for more than eight rounds for the DNA-PRESENT algorithm. It is good to double the number of rounds to obtain complete diffusion as it will provide a larger security margin and confidence interval [81]. According to [81], the number of rounds should be odd as it is a common practice, and there are 16 rounds of encryption with an additional round of key whitening, so the total number of rounds is 17. Hence, full-round DNA-PRESENT is enough to resist the differential attack. Calculating the optimal number of rounds for our proposed design involved using a differential cryptanalysis approach to find the differential trails. It is common to perform differential trails to the secure bound on the number of rounds [13; 29; 81; 82].  
\begin{table}
\begin{tabular}{l l l l l l l l l l l} \hline \hline
**Algorithm** & **Block** & **Key** & **Rounds** & **Tech** & **Cost** & **Latency** & **TP** & **HE** & **FoM** &
\begin{tabular}{l} **Size with Respect** \\ **to DNA-PRESENT** \\ \end{tabular} \\ \hline
**Unit** & **Bits** & **Bits** & & **\(\boldsymbol{\mu}\)m** & **GE** & **Cycles/Block** & **Kb/s** & **Kbps/KGE** & & \\ \hline
**Better Is** & & & **Lower** & **Lower** & **Higher** & **Higher** & **Higher** & **Lower** \\ \hline LED [12; 27] & 64 & 128 & 48 & 0.18 & 1265 & 1872 & 3.4 & 2.68 & 2.12 & 0.50 \\ RECTANcGE [28] & 64 & 128 & 25 & 0.13 & 1787 & 246 & 26 & 137.66 & 8.14 & 0.71 \\ PRESENT [25] & 64 & 128 & 31 & 0.18 & 1886 & 32 & 200 & 106.04 & 56.23 & 0.75 \\ DNA-PRESENT & 64 & 128 & 17 & 0.18 & 2519 & 17 & 376.47 & 149.45 & 59.32 & \\ PUFFIN [12; 26] & 64 & 128 & 32 & 0.18 & 2577 & 32 & 200 & 77.6 & 30.12 & 1.02 \\ mCrypton [12] & 64 & 128 & 12 & 0.18 & 2760 & 190 & 33.51 & 12.14 & 4.40 & 1.10 \\ I-PRESENT [29] & 64 & 128 & 30 & 0.18 & 2783 & 30 & 213.33 & 76.65 & 27.54 & 1.1 \\ NOKEON [23] & 128 & 128 & 16 & 0.18 & 2862 & 3720 & 3.44 & 1.2 & 0.42 & 1.38 \\ PRINCE [12] & 64 & 128 & 11 & 0.13 & 3491 & 533.3 & 12 & 152.77 & 0.98 & 1.47 \\ ICEBERG [24] & 64 & 128 & 16 & 0.18 & 5817 & 16 & 400 & 68.76 & 11.82 & 2.31 \\ AES [13] & 128 & 128 & 10 & 0.13 & 11,031 & 226 & 48 & 4.35 & 0.39 & 4.38 \\ \hline \hline \end{tabular}
\end{table}
Table 11: Cost, latency, throughput, hardware efficiency, FOM, and relative size of block ciphers with SPN structure.  
\begin{table}
\begin{tabular}{l l l} \hline \hline
**Round Number** & **Probability** & **Active s-Boxes** \\ \hline
1 & \(2^{-2}\) & 2 \\
2 & \(2^{-6}\) & 4 \\
3 & \(2^{-18}\) & 4 \\
4 & \(2^{-30}\) & 3 \\
5 & \(2^{-38}\) & 3 \\
6 & \(2^{-47}\) & 6 \\ \hline \hline \end{tabular}
\end{table}
Table 12: Differential trails and number of active s-boxes.