The Absolute Internal Setting ============================= {Remak: the following text is excerpted from TICOM I-175, but the example used is mine} The ciphered message (with indicators): FFJAN ICELP EPRYF AWLLH WJXYR IYIYL YZCQO SROEA FFJAN ICELP The Plain message: REINFORCEMENTS URGENTLY NEEDED Relative Pins setting: 01234567890123456789012345 ABCDEFGHIJKLMNOPQRSTUVWXYZ 10110000110110001101000110 1110010011010100100110100 10111000011010111000111 011000110100111001011 1011101100011010010 01000100100110111 Lugs: 2:12:1:5:10:3 Overlaps (5): 3-6:1 1-6:1 1-5:1 4-5:1 2-5:2 As has been said before, the position of the active and inactive pins on every wheel, relative to the letters on the wheel, must be found. The sequel of the pin positions of every wheel is know, and so are the positions of the drum bar lugs. The sequel of spaces covered by the turns of the printing wheel, from the beginning of the message text, is know. It is found by comparing the clear and cipher text of the message and using the model of the printing wheel. E.g. Clear: R E I N F O R C E M E N T ... Cipher: E P R Y F A W L L H W J X ... Spaces: 22 20 0 12 11 15 14 14 16 20 1 23 17 ... Every spaces is the result from 1 to 5 possible combinations of active or inactive pin positions on the 6 wheels. When the sequel of spaces is long enough, certain sequels of pin positions can be made out. E.g. @ Wheel I: + - + + - - - - + + - + + " II: + + + - - + - - + + - + - " III: + - + + + - - - - + + - + " IV: - + + - - - + + - + - - + " V: + - + + + - + + - - - + + " Vi: - + - - - + - - + - - + + 22 20 0 12 11 15 14 14 16 20 1 23 17 The vertical columns of this table correspond to the 1st, 2nd, 3rd, etc. letter of the message text. The column (@) as corresponding to the first, indicates the pins positions at the letters on every wheel, that move, when the message text begins to be printed. These are the letters referred to as starting positions of the wheels. The idea about the absolute internal setting, is to begin the arrangement or sequel of pin positions (column @) at such letters of the wheels, that when the wheels are turned to initial positions - external indicator - and the single letter of the alphabet is printed, the 1st printing of this letter whill give as cipher the letter, where on wheel I the sequel of pin positions begins; the 2nd printing of the single will give as cipher the letter, where on wheel II the sequel of ping positions begins, etc. E.g. External indicator: FFJAN ICELP. The wheels are turned to the positions Wheel I: J " II: A " III: N " IV: I " V: C " VI: E and the letter F is printed repeatedly, with results as follows: 1st printing: Clear F, by 1st space of the printing wheel, gives cipher @ (wheel I) 2nd printing: Clear F, by 2nd space, gives cipher @ (wheel II) 3rd printing: Clear F, by 3rd space, gives cipher @ (wheel III) 4th printing: Clear F, by 4th space, gives cipher @ (wheel IV) 5th printing: Clear F, bu 5th space, gives cipher @ (wheel V) 6th printing: Clear F, by 6th space, gives cipher @ (wheel VI). The six spaces of turns of the printing wheel can be drawn as a table, e.g. 1 2 3 4 5 6 i=5 Wheel I: - - + + - + (+5 + "J" = 14) j=5 Wheel II: + - - + + - (+5 + "A" = 5) k=16 Wheel III: - - - + + - (+16 + "N" = 29%23=6) l=6 Wheel IV: + - - + - + (+6 + "I" = 14) m=10 Wheel V: + - + - - + (+10 + "C" = 12) n=8 Wheel VI: + - + + + - (+8 + "E" = 12) Spaces: 27 0 13 21 15 15 Clear: F F F F F F ... Cipher: V U H P J J [External Key] i=0..26, j=0..25, k=0..23, l=0..21, m=0..19, n=0..17 If the table is right, the columns (vertical) must be possible combinations of pin positions, but also the lines must be possible sequels of pin positions on the respective wheels, and the letters resulting of clear F and the space in question must be such as exist on the respective wheel. This must be tried and varied so long as to get a table responding to this conditions. When the table is found, the cipher letters resulting by the printing of "FFFFFFF ..." and the spaces shown in the table, give the starting position of the wheels. At these, the sequel of pin positions have to begin (@). The Absolute Pin setting: Wheel I: AB_D___HI_K_MN____ST_VW___ Abs. = Rel. +5 + "L" = Rel. + 16 " II: A__DE_G__JKL__O__RS_U_X__ Abs. = Rel. +5 + "L" = Rel. + 16 " III: AB____GH_J_LMN___RSTU_X Abs. = Rel. +16 + "K" = Rel. +(26%23) " IV: __C_EF_HI___MN_P__STU Abs. = Rel. +6 + "J" = Rel. + 15 " V: _B_DEF_HI___MN_P__S Abs. = Rel. +10 + "I" = Rel. + 18 " VI: AB_D___H__K__NO_Q Abs. = Rel. +8 + "H" = Rel. + 15 LLKJIH = [ 11, 11, 10, 9, 8, 7 ] If External Key = VUHPJJ, Then Active Pins = KJUGBC [+++-+-] (@) "A" -5 = "V" "A" -5 = "U" "A" -16 = "H" "A" -6 = "P" "A" -10 = "J" "A" -8 = "J" Remark: The method described in this paper is not very effective if done manually. The TICOM texts suggest that it took about a week of work. The only effective method is using two different indicators (DF-105). But, nowadays, with a computer, the 100 million positions may be tested very quickly.