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Mhaske and Kumar

                 Table 1. Example of minimum support threshold      5.1. Objective function
                 computations with items and their occurrences      The STI-TSA is deployed to generate optimal keys for
                 Item                                 Occurrence    PP. This algorithm takes into account HFR, MD, and
                 A                                        7         IPR. Consequently, the objective function is represented
                                                                    by Equation IV, where weight is denoted by w.
                 B                                        7
                 C                                        6         OF = min (W  × [1 − IPR] + W  × HFR + W  × MD)     (IV)
                                                                                             2
                                                                               1
                                                                                                        3
                 D                                        2            In Equation IV,
                 E                                        4                  Constraints
                 F                                        4         W                 i                          (V)
                                                                      i
                                                                         Sum of constraints  i
                                                                                                           d
                 Table 2. Frequent items and occurrences               HFR is the proportion of sensitive data P  to the total
                                                                              d
                                                                                   s
                 Items                               Occurrence     count of  P  in  d ,  as  well-defined  in  Equation VI.  In
                                                                    Equation VI, P  specifies the sanitized data.
                                                                                 *
                 A                                        7
                 B                                        7                Count of sensitive data exposed  inP
                 C                                        6          HFR         Count of sensitive data        (VI)
                                                                       MD  offers specifics on the degree of modification
                                                                          38
                 Table 3. Sample dataset                            happening among P  and P , as shown in Equation VII.
                                                                                            *
                                                                                      d
                 Item 1    Item 2    Item 3     Item 4    Item 5
                                                                                         *
                                                                                     D
                 A            B         C                           MD = Euclidean [P , P ]                     (VII)
                 A            C                                        The IPR indicates  the variance  between the count
                                                                                             *
                 B            D         E                           of non-sensitive data and P  to the total count of non-
                 A            C         F                           sensitive data in Equation VIII.
                 A            B         C         D         E              Nonsensitivedatacount  P

                 B            F                                      IPR                                       (VIII)
                                                                             Nonsensitivedatacount

                 Table 4. Dataset after eliminating the uncommon    5.2. Solution encoding
                 items                                              During optimization,  candidate  keys are provided as
                 Item 1    Item 2     Item 3    Item 4    Item 5    input to the STI-TSA. During optimization, STI-TSA
                 A            B         C                           refines the keys continuously based on certain constraints
                 A            C                                     that prioritize effective PP. The iterative procedure of
                 B                                                  STI-TSA strikes a balance, ensuring the candidate keys
                                                                    meet the objectives of preserving privacy in EHRs.
                 A            C
                 A            B         C                           5.2.1. STI-TSA
                 B                                                  Tuna search for their prey using two different foraging
                                                                    techniques. Initially, the population in the field of search
                                                                    space is generated arbitrarily for the TSA’s optimization.
                 Table 5. Generation of item combinations
                                                                    Each tuna chooses one of the two foraging techniques
                 Row 1: AB, AC, BC                                  to use. All TSA individuals were kept informed until the
                 Row 2: AC                                          final requirement was fulfilled. The optimal solution and
                 Row 3: -                                           the corresponding fitness value were then returned. This
                 Row 4: AC                                          section describes the precise model of the STI-TSA.
                                                                       While the TSA offers better solutions, it is prone to
                 Row 5: AB, AC, BC                                  converging to local optima instead of finding the global
                 Row 6: -                                           optimum.  Moreover,  excessive  exploration  can  cause





                Volume 22 Issue 1 (2025)                       156                           doi: 10.36922/AJWEP025040017
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