decryption getting so long

im doing image encryption and decryption

while encrypting the code is running for a couple of seconds

but during decryption it is taking more thn 4hours

also during decyption the matrix is getting printed again and again i have removed all the display commands in the code

[Walter Roberson]

You might be missing a semicolon at the end of an assignment.

You might need to preallocate a variable for performance reasons.

Note that due to the laws of the United States, we can only talk in vague generalities about encryption and decryption code. If the topic were nearly anything else we would ask to see your code, but for this one topic we have to tell you not to post your code.