# Design Trends and Comparative Analysis of Lightweight Block Ciphers for IoTs
## 5 Comparative Analysis
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**No.** & **Cipher** & \
\begin{tabular}{c} **Block** \\ **Size** \\ \end{tabular} &
\begin{tabular}{c} **Key** \\ **Size** \\ \end{tabular} & **Structure** & **Rounds** & **GE** & **Limitation** \\ \hline
16 & LIBC & 64 & 128 & SPN & 31 & 1240 & Tight security margin. \\ \hline
17 & INLEC & 64 & 128 & SPN & 15 & 1953 & Simulated, not field-tested. \\ \hline
18 & LELBC & 64 & 128 & SPN & 20 & 1350 & Limited advanced attack resistance. \\ \hline
19 & LTLBC & 64 & 128 & SPN & 14 & 1967 & Unrolled design is costly; only 64-bit block \\ \hline
20 & GRANULE & 64 & 80 & FN & 32 & 1100 & Lower throughput. \\ \hline
21 &
\begin{tabular}{c} Improved\_DLBCA \\ \end{tabular} & 64 & 80 & FN & 32 & 1024 & Lower active S-boxes. \\ \hline
22 & \
\begin{tabular}{c} Improved\_SIMECK \\ \end{tabular} & 64 & 128 & FN & 32 & 1450 &
\begin{tabular}{c} Reduced randomness; security unverified; \\ complexity increased. \\ \end{tabular} \\ \hline
23 & MANTRA & 64 & 128 & FN & 32 & 1662 & Unverified security margin. \\ \hline
24 & TED & 64 & 128 & FN & 26 & 1400 & Real-time bit permutations increase cost. \\ \hline
25 &
\begin{tabular}{c} Improved\_ROadRunner \\ \end{tabular} & 64 & 80 & FN & 20 & None & Limited parallelism. \\ \hline
26 & LCA & 64 & 256 & FN & 20 & 1700 & Limited advanced cryptanalysis. \\ \hline
27 & M-XXTEA & 64 & 128 & FN & 32 & 1500 & Chaotic keys are hard to sync. \\ \hline
28 & improved\_SM4 & 128 & 128 & FN & 32 & 2803 & Complex composite field. \\ \hline
29 & SCENERY & 64 & 80 & FN & 28 & 1438 & Slow diffusion. \\ \hline
30 & FlexAEAD & 64 & 128 & FN & 32 & 1650 & Not optimized for 64-bit. \\ \hline
31 & LiteEncrypt & 64 & 128 & FN & 24 & 2100 & Unverified side-channel resistance \\ \hline
32 & RBFK & 64 & 128 & FN & 20 & 1200 & Lacks formal and side-channel cryptanalysis \\ \hline
33 & ANU-II & 64 & 80/128 & FN & 25 & 1010 & Limited flexibility; S-box homogeneity \\ \hline
34 & NUX & 64 & 128 & GFN & 31 & 1022 & High round count. \\ \hline
35 & NUCLEAR & 64 & 128 & GFN & 25 & 1100 & Limited testing. \\ \hline
36 & Shadow & 64 & 128 & GFN & 32 & 1250 & Early rounds vulnerable. \\ \hline
37 & HDLBC & 64 & 128 & GFN & 32 & 1248 & Less adaptable. \\ \hline
38 & GFLE & 64 & 128 & GFN & 28 & 1596 & Security margin tight. \\ \hline
39 & IIoTBC & 64 & 128 & GFN & 28 & 1769/2338 & Lacks independent cryptanalysis \\ \hline
40 & \(\mu\)2 & 64 & 80 & GFN & 26 & None & Lacks practical FPGA/ASIC metrics \\ \hline
41 & LPHD & 64 & 128 & GFN & 14 & 1276 & No third-party analysis; side-channel untested \\ \hline
42 & T-TWINE & \
\begin{tabular}{c} 64+ \\ Tweak \\ \end{tabular} & 80/128 & GFN & 36 & 2180 &
\begin{tabular}{c} Higher GE than modern TBCs; limited \\ tweak-related security \\ \end{tabular} \\ \hline
43 & BRIGHT & 64 & 128 & ARX & 28 & 1200 & Unverified new attacks. \\ \hline
44 & LiARX & 64 & 128 & ARX & 30 & 1180 & Weaker non-linearity. \\ \hline
45 & DABC & 64 & 128 & ARX & 30 & 1000 & Complex analysis. \\ \hline
46 & SAECHAM & 64 & 128 & ARX & 88 & 1300 & Scaling issues. \\ \hline
47 & SAND-2 & 64 & 128 & ARX & 28 & 1220 & Round function complexity. \\ \hline  &
\begin{tabular}{c} Hybrid \\ PRESENT and \\ Salsa20 \\ \end{tabular} & 64 & 128 & Hybrid & 20 & 1500 & Reduced rounds lower security. \\ \hline
49 & GFRX & 64 & 128 & Hybrid & 20 & 886 & Low throughput. \\ \hline
50 & FeW & 64 & 128 & Hybrid & 32 & 1400 & Complex key schedule. \\ \hline
51 & ECLBC & 64 & 128 & Hybrid & 28 & 1650 & Lacks dynamic response. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._Figure 45 illustrates the hardware implementation cost of 55 lightweight block ciphers based on their gate equivalents (GEs). This metric represents the area required for implementing each cipher in hardware, with a lower GE indicating better suitability for resource-constrained environments such as IoTs devices and embedded systems. The figure excludes three ciphers (Improved_RoadRunner, u2, and RAZOR) due to the unavailability of reported GE data.