Scram 1.2 03-AUG-92 ==================== Notice ====== "Scram" is copywrite 1991 by Bill J. Phillips. It may be freely distributed as long as the "Scram12.doc" documentation file accompany's the program. I claim no responsibility for the use or implementation of "Scram." Scram12.lha =========== scram - the executable Scram12.doc - documentation (what you're reading now) ScrmDMII.doc - how to use with DiskMaster II Description =========== "Scram" is a program which reads in an ASCII file and outputs the same file in a scrambled (or encrypted ) form. Scram uses a proprietary algorhythm together with a user input password to render the text file unreadable. By using the same password, Scram can then read in the scrambled (encrypted) text file and output the original (de-scrambled) text file. Scram affects only printable ASCII characters in a file and will not alter tabs, line-feeds, etc. or binary (8 bit) characters. The MAIN POINT: ASCII in = ASCII out (pure text in = pure text out) A scrambled text file appears in the same format as the original input file. However there is a five character header of "QZSZQ" or "QZLZQ" added to the beginning of the file and a five character footer "QZFZQ" added at the end of the file. There is also a "dummy" character added as the first character in each line. These features are implemented for on-line use. The dummy characters are upper case A - Z and will repeat if there are more than 26 lines in the file. When doing an ASCII-send the dummy character assures that the first character in each line is an alpha character and not a period or back-slash which some mail systems interpret as a command. If a text file is captured on-line then the scrambled text may be imbedded in a large text file. Scram will search though the file until it finds the header. It will then start to de-scramble the text and continue until it reaches the footer. Only the de-scrambled text will be sent to the output file. If the header is not found a message will print this fact to the screen and the program will end. If the header is found but the footer is not found the de-scramble will work just fine but additional text, if present, will also be sent to the output file. Modes ===== There are two scramble modes: Standard (S) mode, and Line (L) mode. In Standard mode the whole file must remain intact to be de-scrambled. If a character is missing or added then the file will fail to properly de-scramble from that point on. In Line mode each line is separately scrambled. So a discrepancy in one line will only affect the de-scramble of that line, and other lines may still de-scramble properly. The header for standard mode is "QZSZQ". The header for line mode is "QZLZQ". When de-scrambling, the program detects the "S" or "L" in the header to automatically de-scramble in the right mode. Hence, only one de-scramble switch. When doing on-line ASCII-sends where a character may be lost now and then, it is recommended to use Line mode and that the text file consist of lines of less then 79 characters. This is so lines do not wrap around. Either mode will, however, scramble any size text file with lines of any length. And as long as the scrambled file remains in tact it can then be de- scrambled successfuly with the orignal password. Be Aware ======== I've used Scram on 100K textfiles that included some lines with 130 or more characters, no problem - unless the scrambled textfile with these 130 character lines gets "wrapped" at 80 columns (by some word proc or text editor or E-mail system) at which point an extra line is added without and extra "dummy" char at the beginning which can throw things off at that point. Just be aware. Usage ===== The password is not case sensitive. That is, the password "DINGLE" is the same as "dingle". The program format is: scram s or S = standard scramble l or L = line mode scramble d or D = de-scramble password = 5 to 15 alpha chars, case insensitive input_file = any standard file name, may include path output_file = any standard file name, may include path Typing: "scram" with no parameters (or less than 4) will produce the above usage template at the command line. Example ======= text file: "message.doc" password: "killroy" ----------------------------------------------- scram s killroy message.doc note.doc (scrambles file) scram l killroy message.doc note.doc (scrambles file in line mode) scram d killroy note.doc letter.doc (de-scrambles either mode) History ======= 06-AUG-92 - 1.2 - UNIX version, asks for password after it's run as requested by Kenton Phillips, System Mgr at M.I.T 05-AUG-92 - 1.2 - MSDOS version compiled on Amiga 3000 running PC-TASK v1.11 MSDOS emulator and C Ware Personal C v1.2c 03-AUG-92 - 1.2 - Added footer to signal end of scrambled text Made Amiga & MSDOS versions compatable (Amiga v1.1 will not work with MSDOS v1.2 scrambled files) 09-DEC-91 - 1.1 - 1st MSDOS version compiled on 286 machine, Turbo C++ (Thanks Robert Kirchhof, Deland, FL) 06-DEC-91 - 1.1 - Added line-mode option, (1st release version) This source also compiles and runs on Sun SPARC 11-NOV-91 - 1.0 - Amiga only, compiled with SAS C 5.1 on Amiga 3000 (this version not released) Notes For Advanced (Fun) Use ============================ (1) Files that have been encoded with UUENCODE are perfect for use with Scram. A UUENCODE'd file is a pure ASCII file that is a block of text where each line is 60 characters. Try using Scram with either the or the mode switch. The file will then become a block of text that has 61 charcaters in each line - perfect for sending over E-mail systems. (UUENCODE turns a binary file into ASCII, UUDECODE gets back the original binary file. Common on Amigas, UNIX, etc.) (2) Once a textfile has been scrambled using an appropriot password it can then be scrambled again using another password. In other words, you'll have a texfile that has been scrambled twice, each time using a different password. The original file can then only be obtained by de-scrambling the double-scrambled textfile twice using the same two passwords in reverse order. Now you could send the double-scrambled textfile to two different people and give each one of them only one of the two passwords needed to de-scramble the textfile. Neither one of the two people will be able to read the textfile until they get together and exchange passwords. Neato! Of course you could scramble a textfile three or four times using a different password each time; then get the original textfile back by de-srambling the final textfile using the the same passwords in reverse order. Go ahead, experiment. ============================ Bill Jay Phillips 9305 N. Oakleaf Tampa, FL 33612 ---------------------------- Genie: B.Phillips.13 USENET: tbag!jayson@tscs.com ============================