***************************************************************** *** THE ENCRYPTOR *** *** Documentation File *** *** by Larry Schuster *** ***************************************************************** =====> N O T I C E <======= THIS PROGRAM IS SUPPLIED FOR YOUR PERSONAL AND NON-COMMER- CIAL USE ONLY. NO COMMERCIAL USE PERMITTED. USERS OF THIS PROGRAM ARE GRANTED LIMITED RIGHTS TO REPRODUCE AND DIS- TRIBUTE THIS PROGRAM. IT MAY NOT BE SOLD. PROVIDING THIS PROGRAM FOR CONSIDERATION OF ANY SORT, INCLUDING COPYING OR DISTRIBUTION FEES, IS SPECIFICALLY PROHIBITED. THE AUTHOR CANNOT ASSUME RESPONSIBILITY FOR DAMAGES, REAL OR IMAGINED, RESULTING FROM THE USE OF THIS PROGRAM. =====> END NOTICE <======== ----------------------------------------------------------------- Released to the public domain but may not be distributed for commercial purposes or for pay without the express written consent of the author. ------------------------------------------------------------------ This program encrypts ANY disk file into garbage using a propri- etary encryption algorithm. The algorithm has not been released to the public domain, not because the author thinks its all that classified, but to insure that your encrypted data is more se- cure. If BAD GUYS knew the method, it would simply make it that much easier for them to break the encryption. Suffice it to say that the algorithm is EXTREMELY secure and that it would take someone a long, long time on a fast mainframe computer to even- tually decrypt your file, and even then might not get it if they didn't have the original file to work from. The program will securely encrypt DOS files of any type, inclu- ding .COM, .EXE, any ASCII file, BASIC files, etc. In other words; if you got it on your disk, it'll encrypt it and decrypt it back to its original form. The program is a compiled BASIC program. Simply type 'ENCRYPT' from the keyboard, and the program will announce itself and ask you for the file to be encrypted. The program will check to see it the file you input exists. If it doesn't, you'll be asked to retype it. Next, you will be asked for three keywords and a random number seed. It cannot be said strongly enough....REMEMBER THESE KEY- WORDS AND THE RANDOM NUMBER SEED. If, perchance, you should forget the keywords or the random number seed, kiss your file goodbye. Truly, truly, truly...it's gone. Don't call me or any- one else to try to rescue it. Knowledge of the algorithm used to encrypt the file is insufficient to decrypt the file. If, how- ever, you simply typed the keywords or the seed in wrong, you can rescue the file by decrypting the file with the incorrect entries and then decrypting it again with the correct ones. As might have occurred to you by now, you can encrypt an encrypted file as many times as you wish; and, as long as you decrypt it cor- rectly, ie., in EXACTLY the reverse fashion, the last encryption first, etc. and with EXACTLY the correct keywords and seed number for each level of encryption, you'll get your file back. Files are decrypted in exactly the same fashion as they are encrypted. Simply type in the keywords and random number seed used to encrypt them, and it will decrypt the file back to its original form. Don't ever stop the encryption process once its started or you'll have lost the file. The program is reading in the file one 128 byte sector at a time, encrypting it and writing it out over the original sector. If you stop the program while it's executing, you'll have a file that's partly encrypted and partly not. Thus, if you try to get it back, the encrypted part will be decrypted and the decrypted part will be encrypted. If you've made a mistake, say in misspelling a keyword, just let it finish and then decrypt it with the same misspelled keyword, THEN try again with the correct keywords. The program will offer you the opportunity to change the random number generator constants. The program contains its own random number constants which produce a very uniform set of random numbers. But let's say you want to exchange encrypted files with several people, and you want them to be able to decrypt only files generated by a specific set of numbers. Anyone else with the ENCRYPTOR program could decrypt your files if they got hold of your keywords and seed numbers. If, however, each person gets a different set of random number constants, then they can only decrypt files encrypted with that particular set of random num- bers. The file ENCRYPT.DAT will contain the numbers you select. The program checks the currently logged disk (be careful if your're on A: and the file is on B:) to see if ENCRYPT.DAT exists. If it does, it will use the numbers it gets from the file for the random number generator. If, for any reason, it doesn't find the file, it will use the internally stored random numbers for the generator. Thus, it is critical that everyone who uses this option understand that ENCRYPT.DAT must always be present on the currently logged disk whenever they wish to de- crypt files encrypted by you and that if they change the random numbers themselves, that the original numbers will be overwrit- ten. If you want to change the numbers and you already have ENCRYPT.DAT on the disk, change its name to something else from DOS before you use the option. Remember that lack of the ENCRYPT.DAT file only means that the internal numbers will be used, not that encryption will be stopped. The last option allows you to retain the keywords and random number seed on the screen while encrypting or to erase them from prying eyes while the encryption proceeds. This is your last chance to insure that you have them correct. Remember, once its gone, its gone. The program encrypts files at about the rate of 768 bytes/second on the IBM-PC so you should take that into account when you're encrypting a 40K file (that's about 52 minutes, folks). The program will ask you if you want to encrypt another file when its through. If you don't, you'll be returned to DOS; if you do, the program will restart. ***************************************************************** Program Author: Larry Schuster 3816 Academy Parkway North, N.E. Albuquerque, New Mexico 87109 (505) 344-3523 ***************************************************************** e, New Mexico 87109 (505) 344-3523