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- Phrack Seventeen
- 07 April 1988
-
- File 9 of 12 : Data-Tapping Made Easy
-
-
- --FEATURE ARTICLES AND REVIEWS-
-
-
- TAPPING COMPUTER DATA IS EASY, AND CLEARER THAN PHONE CALLS !
-
- BY RIC BLACKMON, SYSOP OF A FED BBS
- Aquired by Elric of Imrryr & Lunatic Labs UnLtd
- Note from Elric: This file was written by the sysop of a board for
- computer security people (run on a CoCo), as far as I know the board
- no longer exists, it was being crashed by hackers too much... (hehe).
- ---------------------
-
- FOR SEVERAL YEARS, I ACCEPTED CERTAIN BITS OF MISINFORMA-
- TION AS TECHNICALLY ACCURATE, AND DIDN'T PROPERLY PURSUE THE
- MATTER. SEVERAL FOOLS GAVE ME FOOLISH INFORMATION, SUCH AS:
- A TAP INTERRUPTS COMPUTER DATA TRANSMISSIONS; DATA COULD BE
- PICKED UP AS RF EMANATIONS BUT IT WAS A MASS OF UNINTELLIGIBLE
- SIGNAL CAUSED BY DATA MOVING BETWEEN REGISTERS; ONE HAD TO BE IN
- 'SYNC' WITH ANY SENDING COMPUTER; DATA COULDN'T BE READ UNLESS
- YOU HAD A DIRECT MATCH IN SPEED, PARITY & BIT PATTERN; AND ONLY A
- COMPUTER OF THE SAME MAKE AND MODEL COULD READ THE SENDING COM-
- PUTER. THIS IS ALL PLAIN SWILL. IT IS IN FACT, AN EASIER CHORE TO
- TAP A COMPUTER THAN A TELEPHONE. THE TECHNIQUE AND THE EQUIPMENT
- IS ALMOST THE SAME, BUT THE COMPUTER LINE WILL BE MORE ACCURATE
- (THE TWO COMPUTERS INVOLVED, HAVE ERROR CORRECTING PROCEDURES)
- AND CLEARER (DIGITAL TRANSMISSIONS HAVE MORE DISTINCT SIGNALS
- THAN ANALOG TRANSMISSIONS).
-
- FIRST, RECOGNIZE THAT NEARLY ALL DATA TRANSMISSIONS ARE SENT IN
- CLEARTEXT ASCII SIGNALS. THE LINES CARRYING OTHER BIT-GROUPS OR
- ENCYPHERED TEXTS ARE RARE. SECOND, THE SIGNAL APPEARS ON GREEN
- AND RED (WIRES) OF THE PHONE LINE ('TIP' AND 'RING'). THE DATA IS
- MOST LIKELY ASYSCHRONOUS SERIAL DATA MOVING AT 300 BAUD. NOW THAT
- 1200 BAUD IS BECOMING MORE CHIC, YOU CAN EXPECT TO FIND A GROWING
- USE OF THE FASTER TRANSMISSION RATE. FINALLY, YOU DON'T NEED TO
- WORRY ABOUT THE PROTOCOL OR EVEN THE BAUD RATE(SPEED) UNTIL AFTER
- A TAPED COPY OF A TRANSMISSION IS OBTAINED.
-
- IN A SIMPLE EXPERIMENT, A TAPED COPY OF A DATA TRANSMIS-
- SION WAS MADE WITH THE CHEAPEST OF TAPE RECORDERS, TAPPING THE
- GREEN AND RED LINES BEYOND THE MODEM. THE RECORDING WAS THEN
- PLAYED INTO A MODEM AS THOUGH IT WERE AN ORIGINAL TRANSMISSION.
- AT THAT POINT, HAD IT BEEN NECESSARY, THE PROTOCOL SETTINGS ON
- RECEIVING TERMINAL COULD HAVE BEEN CHANGED TO MATCH THE TAPE. NO
- ADJUSTMENTS WERE NECESSARY AND A NICE, CLEAR ERROR-FREE DOCUMENT
- WAS RECEIVED ON THE ILLICIT VIDEO SCREEN AND A NEAT HARD-COPY OF
- THE DOCUMENT CAME OFF THE PRINTER. THE MESSAGE WAS INDEED CAP-
- TURED, BUT HAD IT BEEN AN INTERCEPTION INSTEAD OF A SIMPLE MONI-
- TORING, IT COULD HAVE BEEN ALTERED WITH A SIMPLE WORD PROCESSOR
- PROGRAM, TO SUIT ANY PURPOSE, AND PLACED BACK ON THE WIRE.
-
- WERE I TO HAVE AN INTEREST IN INFORMATION ORIGINATING
- FROM A PARTICULAR COMPANY, AGENCY, OR OFFICE, I THINK THAT I
- WOULD FIND IT FAR MORE PRODUCTIVE TO TAP A DATA TRANSMISSION THAN
- TO TAP A VOICE TRANSMISSION, AND EVEN MORE REWARDING THAN GETTING
- HARDCOPY DOCUMENTS.
-
- *SIGNIFICANT & IMPORTANT INFORMATION IS MORE CONCENTRATED
- IN A DATA TRANSMISSION. *SIGNIFICANT & IMPORTANT INFOR-
- MATION IS MORE EASILY LOCATED IN DATA TRANSMISSIONS THAN IN
- MASSES OF FILES OR PHONE CALLS. *TRANSMITTED DATA IS
- PRESUMED TRUE, AND WHEN ALTERATION IS DISCOVERED, ITS READILY
- BLAMED ON THE EQUIPMENT. *THE LAWS CONCERNING TAPS ON
- UNCLASSIFIED AND NON-FINANCIAL COMPUTER DATA ARE EITHER QUITE
- LACKING OR ABJECTLY STUPID.
-
- THE POINT OF ALL THIS IS THAT THE PRUDENT MANAGER REALLY OUGHT TO
- ENCRYPT ALL DATA TRANSMISSIONS. ENCRYPTION PACKAGES ARE CHEAP (A
- 'DES' PROGRAM IS NOW PRICED AT $30) AND ARE EASY TO USE.
-
- -------------------------------
-
-
- The Sorceress
-
-
-
- From Lunatic Labs UnLtd. 415-278-7421