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Fig. 22 The generation time for hash when the size of file is 15 MB

Fig. 23 The number of blocks in file size 15 MB difference depending on the size of each block

KB

than about two MB, then the time of execution difference begins to increase as the

block size increases. However, after several experiments, it was found that the time

difference between the two methods does not exceed one minute, regardless of the

size of the file, when choosing the ideal size for the block, which is: Block size =

File size/2. The time at which the hash was created if it was created from data only

or from previous data and hash and the time stamp, where the file size will be fixed

(15 MB or 30 MB), and the hash size of each block in the chain will be variable, and

we also show the difference in the number of blocks in each chain depending on the

size of the blocks (partition), as shown in Figs. 22, 23, 24 and 25.

The number of blocks for a file (represents the number of records in the database

for that file) represents the number of attacks that data can be exposed to, the more

records there are, the more vulnerable they are to attackers, and vice versa, and

therefore the data should be divided into the minimum number of blocks. The number

of blocks of a file varies according to the size of each block and the size of the original

file.