## 3 The Proposed IoMT Model
### Secure Data Transmission and Storage
As can be seen from Tables 8 and 9, SKAC(\(i\),\(j\))/SPAC(\(i\),\(j\)) values are not exactly 0.5 as expected, but the values are very close to the expected value. The absolute error of each SKAC(\(i\),\(j\)) can be obtained using Equations (8) and (9), respectively. \[ \begin{array}{c}\text{er(i,j)}\\ 0\leq i,j\leq n\end{array} =\left|2*\left(\text{SKAC}_{(i,j)}\right)-1\right| \tag{8}\]

\[ \begin{array}{c}\text{er(i,j)}\\ 0\leq i,j\leq n\end{array} =\left|2*\left(\text{SPAC}_{(i,j)}\right)-1\right| \tag{9}\]

The maximum absolute errors eSKAC and eSPAC are obtained by applying Equations (10) and (11), respectively:

\[\text{eSKAC}=\max\limits_{1\leq i,j\leq n}\left|2*\left(\text{SKAC}_{(i,j)} \right)-1\right| \tag{10}\]

\[\text{eSPAC}=\max\limits_{1\leq i,j\leq n}\left|2*\left(\text{SPAC}_{(i,j)} \right)-1\right| \tag{11}\]

The obtained values for eSKAC and eSPAC are 0.0284 and 0.0396, respectively. Substituting the values of eSKAC and eSPAC in Equation (6), the interval of SKAC can be written as:

\[\frac{1}{2}(1-0.0284)\leq SKAC_{(i,j)}\leq\frac{1}{2}(1+0.0284)=0.4858\leq SKAC _{(i,j)}\leq 0.5142\] \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline
**\(i\)/j** & **0** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **13** & **14** & **15** \\ \hline
0 & 0.4954 & 0.5019 & 0.4977 & 0.4942 & 0.4959 & 0.4966 & 0.4924 & 0.4975 & 0.502 & 0.5056 & 0.5056 & 0.4945 & 0.4964 & 0.4977 & 0.4995 & 0.4977 \\
1 & 0.5031 & 0.4944 & 0.507 & 0.4994 & 0.506 & 0.4987 & 0.5049 & 0.4986 & 0.4888 & 0.5004 & 0.5026 & 0.5049 & 0.4973 & 0.4983 & 0.499 & 0.5059 \\
2 & 0.5049 & 0.494 & 0.5039 & 0.4997 & 0.5027 & 0.4973 & 0.5049 & 0.5008 & 0.5023 & 0.5084 & 0.5005 & 0.5005 & 0.5027 & 0.5002 & 0.4957 \\
3 & 0.5036 & 0.4985 & 0.502 & 0.4973 & 0.5006 & 0.5031 & 0.4984 & 0.5047 & 0.5027 & 0.5077 & 0.4952 & 0.4941 & 0.4929 & 0.4973 & 0.4998 & 0.5073 \\
4 & 0.4986 & 0.4889 & 0.499 & 0.4952 & 0.5059 & 0.4952 & 0.508 & 0.5038 & 0.5005 & 0.4951 & 0.4951 & 0.4988 & 0.4942 & 0.4961 & 0.4923 & 0.4946 \\
5 & 0.4999 & 0.4948 & 0.5021 & 0.497 & 0.4966 & 0.4941 & 0.5052 & 0.4942 & 0.4945 & 0.5072 & 0.4948 & 0.4963 & 0.4921 & 0.4957 & 0.498 & 0.5012 \\
6 & 0.5047 & 0.4858 & 0.5002 & 0.4933 & 0.4981 & 0.5012 & 0.5061 & 0.4909 & 0.4967 & 0.4875 & 0.502 & 0.4973 & 0.5064 & 0.4905 & 0.5047 & 0.4994 \\
7 & 0.5004 & 0.4992 & 0.5059 & 0.4984 & 0.4943 & 0.4991 & 0.4952 & 0.4919 & 0.501 & 0.4941 & 0.4996 & 0.4982 & 0.4991 & 0.5009 & 0.5102 & 0.4945 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Strict Key Avalanche Criterion (SKAC). \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c} \hline \hline
**\(i\)/j** & **0** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **13** & **14** & **15** \\ \hline
0 & 0.4913 & 0.4879 & 0.4975 & 0.4977 & 0.4898 & 0.5041 & 0.4987 & 0.5055 & 0.4928 & 0.4938 & 0.4877 & 0.4938 & 0.4957 & 0.4946 & 0.4896 & 0.5059 \\
1 & 0.4881 & 0.4927 & 0.5088 & 0.4891 &\[\frac{1}{2}(1-0.0396)\leq SKAC_{(i,j)}\leq\frac{1}{2}(1+0.0396)=0.4802\leq SKAC_{(i,j )}\leq 0.5198\]

Figures 8 and 9 show the distribution of eSKAC and eSPAC of HMCC, respectively. It can be seen from these Figures that only an insignificant number of bits have error values that are very close to eSKAC and eSPAC, respectively. eSKAC is less than 3, while eSPAC is less than 4. HMCC can, therefore, be said to have satisfied SKAC and SPAC within the range of very small error values. ### Encryption and Decryption Time Analysis

A desirable encryption technique is resistant to cryptanalysis assaults while also being quick enough for real-time applications. 1171 symbols require only 0.593 s to encrypt and 0.565 s to decipher. As a result, HMCC is quick at both encrypting plaintext to produce ciphertext and decrypting ciphertext to produce plaintext. Hence, HMCC can be used in real-time applications. Figure 8: Histogram of SKAC error distribution of HMCC over bit positions.