Qbasic/QuickBasic Programming

Imagine if you took each byte of any file; copied each ASCII Character to a separate slip of paper; placed all of the slips into a paper bag; shook the bag well; and then laid them all out randomly. That is what this program does digitally. Once you choose a file to (ONLY) read, you then choose to either Scramble or Unscramble that file into a new file. Next, you choose a pseudo-random seed, which must be known to once again restore a copy of the original file. You actually have two choices: If you choose to <S>cramble a file, you then must <U>nscramble it for an exact copy restoration; If you choose to <U>nscramble a file, you then must <S>cramble it for an exact copy restoration. If you examine the source code, you will see that this is accomplished by using an index bit-array to keep track of which byte from the original file has already been written to the new scrambled file. Each byte in the original file is represented by one bit in the index bit-array; therefore the bit-array is only 1/8th the size of the original file. One use of this program would be to scramble a file that was already encrypted. This would add another layer of security and make it much more difficult to decrypt the file since it would first have to be unscrambled correctly before the decryption could be accomplished. In the attached zip file is the source code; a Windows compiled executable; and a file named SCRAMBLED.TXT. This file is a scrambled HTM of a well-known science fiction short story and was scrambled with the seed 12345.67 The original.htm was 94,372 bytes long and it took about 51.5 seconds to <S>cramble. First, look at this file in a text editor so that you can see just how well it is scrambled. Then using the seed as mentioned above, <U>nscramble it to any file name you choose with an .HTM or .HTML extension, and enjoy the well-known short story in your browser.

Source included - QB64 - 437.21 KB - 1951 downloads

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