Re: discover encryption method



if i understand you correctly this is a recoverable cipher which uses
only some form of encoding and no key? it should be fairly easy to
decode since a simple repetition analysis shows a number of interesting
characteristics. there are a number of 2 letter repetitions and also
some 3 letter ones and the most common factor of the distance between
these repetitions is also 2. the encoding probably uses a 2 letter
encoding mechanism, this reminds me of a simple hex encoding but it
seems that all 26 alphabetical letters are used. i'm assuming the 3
letter repetitions are non crucial to the encoding, if only uppercase
alphabetical letters are used and 2 are used at a time this gives 676
possible pairs. in case you're interested i've included my analysis of
the first 2 pieces of cipher text you provided.

i'd suggest reverse engineering the program rather than trying to figure
out the encoding yourself, is this a publicly available piece of
software or something you are allowed to distribute?

s3c

*REP ANALISYS OF A.TXT*
TOTAL LEN: 166
"CC" AT 1 REP AT 35, DIS 34, FACTORS OF DIS: 2 17
"CC" AT 1 REP AT 36, DIS 35, FACTORS OF DIS: 5 7
"MC" AT 3 REP AT 143, DIS 140, FACTORS OF DIS: 2 70 4 35 5 28 7 20 10 14
"CA" AT 4 REP AT 33, DIS 29, FACTORS OF DIS:
"CA" AT 4 REP AT 110, DIS 106, FACTORS OF DIS: 2 53
"AA" AT 5 REP AT 23, DIS 18, FACTORS OF DIS: 2 9 3 6
"AA" AT 5 REP AT 80, DIS 75, FACTORS OF DIS: 3 25 5 15
"AA" AT 5 REP AT 95, DIS 90, FACTORS OF DIS: 2 45 3 30 5 18 6 15 9 10
"AA" AT 5 REP AT 125, DIS 120, FACTORS OF DIS: 2 60 3 40 4 30 5 24 6 20
8 15 10 12
"AJ" AT 6 REP AT 24, DIS 18, FACTORS OF DIS: 2 9 3 6
"JE" AT 7 REP AT 25, DIS 18, FACTORS OF DIS: 2 9 3 6
"EG" AT 8 REP AT 78, DIS 70, FACTORS OF DIS: 2 35 5 14 7 10
"EG" AT 8 REP AT 139, DIS 131, FACTORS OF DIS:
"DB" AT 10 REP AT 83, DIS 73, FACTORS OF DIS:
"EI" AT 12 REP AT 64, DIS 52, FACTORS OF DIS: 2 26 4 13
"EI" AT 12 REP AT 67, DIS 55, FACTORS OF DIS: 5 11
"EI" AT 12 REP AT 97, DIS 85, FACTORS OF DIS: 5 17
"IC" AT 13 REP AT 71, DIS 58, FACTORS OF DIS: 2 29
"CE" AT 14 REP AT 72, DIS 58, FACTORS OF DIS: 2 29
"CE" AT 14 REP AT 138, DIS 124, FACTORS OF DIS: 2 62 4 31
"CE" AT 14 REP AT 159, DIS 145, FACTORS OF DIS: 5 29
"AE" AT 21 REP AT 96, DIS 75, FACTORS OF DIS: 3 25 5 15
"AE" AT 21 REP AT 104, DIS 83, FACTORS OF DIS:
"AA" AT 23 REP AT 80, DIS 57, FACTORS OF DIS: 3 19
"AA" AT 23 REP AT 95, DIS 72, FACTORS OF DIS: 2 36 3 24 4 18 6 12 8 9
"AA" AT 23 REP AT 125, DIS 102, FACTORS OF DIS: 2 51 3 34 6 17
"OE" AT 28 REP AT 57, DIS 29, FACTORS OF DIS:
"ED" AT 29 REP AT 89, DIS 60, FACTORS OF DIS: 2 30 3 20 4 15 5 12 6 10
"EB" AT 31 REP AT 105, DIS 74, FACTORS OF DIS: 2 37
"EB" AT 31 REP AT 118, DIS 87, FACTORS OF DIS: 3 29
"CA" AT 33 REP AT 110, DIS 77, FACTORS OF DIS: 7 11
"AC" AT 34 REP AT 81, DIS 47, FACTORS OF DIS:
"AC" AT 34 REP AT 137, DIS 103, FACTORS OF DIS:
"AC" AT 34 REP AT 158, DIS 124, FACTORS OF DIS: 2 62 4 31
"CD" AT 37 REP AT 82, DIS 45, FACTORS OF DIS: 3 15 5 9
"CD" AT 37 REP AT 144, DIS 107, FACTORS OF DIS:
"JH" AT 41 REP AT 45, DIS 4, FACTORS OF DIS: 2 2
"HP" AT 42 REP AT 75, DIS 33, FACTORS OF DIS: 3 11
"MJ" AT 44 REP AT 149, DIS 105, FACTORS OF DIS: 3 35 5 21 7 15
"HG" AT 46 REP AT 51, DIS 5, FACTORS OF DIS:
"GL" AT 47 REP AT 52, DIS 5, FACTORS OF DIS:
"GL" AT 47 REP AT 121, DIS 74, FACTORS OF DIS: 2 37
"OA" AT 49 REP AT 94, DIS 45, FACTORS OF DIS: 3 15 5 9
"OA" AT 49 REP AT 115, DIS 66, FACTORS OF DIS: 2 33 3 22 6 11
"GL" AT 52 REP AT 121, DIS 69, FACTORS OF DIS: 3 23
"AO" AT 54 REP AT 164, DIS 110, FACTORS OF DIS: 2 55 5 22 10 11
"EE" AT 58 REP AT 88, DIS 30, FACTORS OF DIS: 2 15 3 10 5 6
"EE" AT 59 REP AT 88, DIS 29, FACTORS OF DIS:
"EJ" AT 60 REP AT 162, DIS 102, FACTORS OF DIS: 2 51 3 34 6 17
"EI" AT 64 REP AT 67, DIS 3, FACTORS OF DIS:
"EI" AT 64 REP AT 97, DIS 33, FACTORS OF DIS: 3 11
"IE" AT 66 REP AT 85, DIS 19, FACTORS OF DIS:
"IE" AT 66 REP AT 131, DIS 65, FACTORS OF DIS: 5 13
"EI" AT 67 REP AT 97, DIS 30, FACTORS OF DIS: 2 15 3 10 5 6
"CE" AT 72 REP AT 138, DIS 66, FACTORS OF DIS: 2 33 3 22 6 11
"CE" AT 72 REP AT 159, DIS 87, FACTORS OF DIS: 3 29
"PG" AT 76 REP AT 120, DIS 44, FACTORS OF DIS: 2 22 4 11
"EG" AT 78 REP AT 139, DIS 61, FACTORS OF DIS:
"GA" AT 79 REP AT 107, DIS 28, FACTORS OF DIS: 2 14 4 7
"GA" AT 79 REP AT 157, DIS 78, FACTORS OF DIS: 2 39 3 26 6 13
"AA" AT 80 REP AT 95, DIS 15, FACTORS OF DIS: 3 5
"AA" AT 80 REP AT 125, DIS 45, FACTORS OF DIS: 3 15 5 9
"AC" AT 81 REP AT 137, DIS 56, FACTORS OF DIS: 2 28 4 14 7 8
"AC" AT 81 REP AT 158, DIS 77, FACTORS OF DIS: 7 11
"CD" AT 82 REP AT 144, DIS 62, FACTORS OF DIS: 2 31
"IE" AT 85 REP AT 131, DIS 46, FACTORS OF DIS: 2 23
"OA" AT 94 REP AT 115, DIS 21, FACTORS OF DIS: 3 7
"AA" AT 95 REP AT 125, DIS 30, FACTORS OF DIS: 2 15 3 10 5 6
"AE" AT 96 REP AT 104, DIS 8, FACTORS OF DIS: 2 4
"IB" AT 98 REP AT 153, DIS 55, FACTORS OF DIS: 5 11
"KA" AT 101 REP AT 136, DIS 35, FACTORS OF DIS: 5 7
"KA" AT 101 REP AT 155, DIS 54, FACTORS OF DIS: 2 27 3 18 6 9
"AI" AT 102 REP AT 152, DIS 50, FACTORS OF DIS: 2 25 5 10
"EB" AT 105 REP AT 118, DIS 13, FACTORS OF DIS:
"GA" AT 107 REP AT 157, DIS 50, FACTORS OF DIS: 2 25 5 10
"AG" AT 108 REP AT 156, DIS 48, FACTORS OF DIS: 2 24 3 16 4 12 6 8
"GC" AT 109 REP AT 128, DIS 19, FACTORS OF DIS:
"AK" AT 116 REP AT 126, DIS 10, FACTORS OF DIS: 2 5
"AK" AT 116 REP AT 135, DIS 19, FACTORS OF DIS:
"AK" AT 116 REP AT 146, DIS 30, FACTORS OF DIS: 2 15 3 10 5 6
"DA" AT 124 REP AT 134, DIS 10, FACTORS OF DIS: 2 5
"DA" AT 124 REP AT 145, DIS 21, FACTORS OF DIS: 3 7
"DA" AT 124 REP AT 151, DIS 27, FACTORS OF DIS: 3 9
"AK" AT 126 REP AT 135, DIS 9, FACTORS OF DIS: 3 3
"AK" AT 126 REP AT 146, DIS 20, FACTORS OF DIS: 2 10 4 5
"KG" AT 127 REP AT 147, DIS 20, FACTORS OF DIS: 2 10 4 5
"DA" AT 134 REP AT 145, DIS 11, FACTORS OF DIS:
"DA" AT 134 REP AT 151, DIS 17, FACTORS OF DIS:
"AK" AT 135 REP AT 146, DIS 11, FACTORS OF DIS:
"KA" AT 136 REP AT 155, DIS 19, FACTORS OF DIS:
"AC" AT 137 REP AT 158, DIS 21, FACTORS OF DIS: 3 7
"CE" AT 138 REP AT 159, DIS 21, FACTORS OF DIS: 3 7
"DA" AT 145 REP AT 151, DIS 6, FACTORS OF DIS: 2 3
"AAJ" AT 5 REP AT 23, DIS 18, FACTORS OF DIS: 2 9 3 6
"AJE" AT 6 REP AT 24, DIS 18, FACTORS OF DIS: 2 9 3 6
"ICE" AT 13 REP AT 71, DIS 58, FACTORS OF DIS: 2 29
"HGL" AT 46 REP AT 51, DIS 5, FACTORS OF DIS:
"AKG" AT 126 REP AT 146, DIS 20, FACTORS OF DIS: 2 10 4 5
"DAK" AT 134 REP AT 145, DIS 11, FACTORS OF DIS:
"ACE" AT 137 REP AT 158, DIS 21, FACTORS OF DIS: 3 7
"AAJE" AT 5 REP AT 23, DIS 18, FACTORS OF DIS: 2 9 3 6
*FACTOR OCCURENCES*
2 OCCURS 50 TIMES
3 OCCURS 43 TIMES
5 OCCURS 31 TIMES
6 OCCURS 21 TIMES
4 OCCURS 15 TIMES
10 OCCURS 15 TIMES
7 OCCURS 14 TIMES
9 OCCURS 13 TIMES
15 OCCURS 13 TIMES
11 OCCURS 10 TIMES
29 OCCURS 6 TIMES
14 OCCURS 4 TIMES
8 OCCURS 4 TIMES
17 OCCURS 4 TIMES
22 OCCURS 4 TIMES
25 OCCURS 4 TIMES
12 OCCURS 4 TIMES
13 OCCURS 3 TIMES
24 OCCURS 3 TIMES
18 OCCURS 3 TIMES
20 OCCURS 3 TIMES
30 OCCURS 3 TIMES
31 OCCURS 3 TIMES
35 OCCURS 3 TIMES
26 OCCURS 2 TIMES
28 OCCURS 2 TIMES
33 OCCURS 2 TIMES
34 OCCURS 2 TIMES
23 OCCURS 2 TIMES
37 OCCURS 2 TIMES
51 OCCURS 2 TIMES
62 OCCURS 2 TIMES
16 OCCURS 1 TIMES
36 OCCURS 1 TIMES
27 OCCURS 1 TIMES
39 OCCURS 1 TIMES
40 OCCURS 1 TIMES
45 OCCURS 1 TIMES
21 OCCURS 1 TIMES
53 OCCURS 1 TIMES
55 OCCURS 1 TIMES
60 OCCURS 1 TIMES
19 OCCURS 1 TIMES
70 OCCURS 1 TIMES

*REP ANALISYS OF AA.TXT*
TOTAL LEN: 187
"BO" AT 1 REP AT 32, DIS 31, FACTORS OF DIS:
"OB" AT 2 REP AT 41, DIS 39, FACTORS OF DIS: 3 13
"BD" AT 3 REP AT 131, DIS 128, FACTORS OF DIS: 2 64 4 32 8 16
"AH" AT 6 REP AT 170, DIS 164, FACTORS OF DIS: 2 82 4 41
"HG" AT 7 REP AT 80, DIS 73, FACTORS OF DIS:
"DM" AT 9 REP AT 164, DIS 155, FACTORS OF DIS: 5 31
"JN" AT 11 REP AT 183, DIS 172, FACTORS OF DIS: 2 86 4 43
"NE" AT 12 REP AT 125, DIS 113, FACTORS OF DIS:
"EE" AT 13 REP AT 26, DIS 13, FACTORS OF DIS:
"EM" AT 14 REP AT 100, DIS 86, FACTORS OF DIS: 2 43
"BI" AT 16 REP AT 38, DIS 22, FACTORS OF DIS: 2 11
"ID" AT 17 REP AT 35, DIS 18, FACTORS OF DIS: 2 9 3 6
"ID" AT 17 REP AT 67, DIS 50, FACTORS OF DIS: 2 25 5 10
"DO" AT 18 REP AT 28, DIS 10, FACTORS OF DIS: 2 5
"CG" AT 21 REP AT 83, DIS 62, FACTORS OF DIS: 2 31
"CG" AT 21 REP AT 178, DIS 157, FACTORS OF DIS:
"GA" AT 22 REP AT 84, DIS 62, FACTORS OF DIS: 2 31
"AC" AT 23 REP AT 111, DIS 88, FACTORS OF DIS: 2 44 4 22 8 11
"AC" AT 23 REP AT 153, DIS 130, FACTORS OF DIS: 2 65 5 26 10 13
"AC" AT 23 REP AT 159, DIS 136, FACTORS OF DIS: 2 68 4 34 8 17
"AC" AT 23 REP AT 161, DIS 138, FACTORS OF DIS: 2 69 3 46 6 23
"FE" AT 25 REP AT 55, DIS 30, FACTORS OF DIS: 2 15 3 10 5 6
"FE" AT 25 REP AT 72, DIS 47, FACTORS OF DIS:
"ED" AT 27 REP AT 121, DIS 94, FACTORS OF DIS: 2 47
"ED" AT 27 REP AT 136, DIS 109, FACTORS OF DIS:
"OE" AT 29 REP AT 135, DIS 106, FACTORS OF DIS: 2 53
"EH" AT 30 REP AT 90, DIS 60, FACTORS OF DIS: 2 30 3 20 4 15 5 12 6 10
"EH" AT 30 REP AT 141, DIS 111, FACTORS OF DIS: 3 37
"ID" AT 35 REP AT 67, DIS 32, FACTORS OF DIS: 2 16 4 8
"DC" AT 36 REP AT 64, DIS 28, FACTORS OF DIS: 2 14 4 7
"CB" AT 37 REP AT 127, DIS 90, FACTORS OF DIS: 2 45 3 30 5 18 6 15 9 10
"IC" AT 39 REP AT 157, DIS 118, FACTORS OF DIS: 2 59
"CO" AT 40 REP AT 162, DIS 122, FACTORS OF DIS: 2 61
"BF" AT 42 REP AT 54, DIS 12, FACTORS OF DIS: 2 6 3 4
"FH" AT 43 REP AT 108, DIS 65, FACTORS OF DIS: 5 13
"BE" AT 46 REP AT 99, DIS 53, FACTORS OF DIS:
"BE" AT 46 REP AT 140, DIS 94, FACTORS OF DIS: 2 47
"CN" AT 52 REP AT 65, DIS 13, FACTORS OF DIS:
"FE" AT 55 REP AT 72, DIS 17, FACTORS OF DIS:
"EG" AT 56 REP AT 123, DIS 67, FACTORS OF DIS:
"GB" AT 57 REP AT 185, DIS 128, FACTORS OF DIS: 2 64 4 32 8 16
"BH" AT 58 REP AT 79, DIS 21, FACTORS OF DIS: 3 7
"HP" AT 59 REP AT 151, DIS 92, FACTORS OF DIS: 2 46 4 23
"EA" AT 61 REP AT 146, DIS 85, FACTORS OF DIS: 5 17
"AF" AT 62 REP AT 71, DIS 9, FACTORS OF DIS: 3 3
"EC" AT 73 REP AT 126, DIS 53, FACTORS OF DIS:
"DL" AT 77 REP AT 132, DIS 55, FACTORS OF DIS: 5 11
"CG" AT 83 REP AT 178, DIS 95, FACTORS OF DIS: 5 19
"LA" AT 87 REP AT 110, DIS 23, FACTORS OF DIS:
"LA" AT 87 REP AT 169, DIS 82, FACTORS OF DIS: 2 41
"AG" AT 88 REP AT 147, DIS 59, FACTORS OF DIS:
"EH" AT 90 REP AT 141, DIS 51, FACTORS OF DIS: 3 17
"HJ" AT 91 REP AT 142, DIS 51, FACTORS OF DIS: 3 17
"JC" AT 93 REP AT 177, DIS 84, FACTORS OF DIS: 2 42 3 28 4 21 6 14 7 12
"CH" AT 94 REP AT 150, DIS 56, FACTORS OF DIS: 2 28 4 14 7 8
"BE" AT 99 REP AT 140, DIS 41, FACTORS OF DIS:
"KH" AT 103 REP AT 118, DIS 15, FACTORS OF DIS: 3 5
"LA" AT 110 REP AT 169, DIS 59, FACTORS OF DIS:
"AC" AT 111 REP AT 153, DIS 42, FACTORS OF DIS: 2 21 3 14 6 7
"AC" AT 111 REP AT 159, DIS 48, FACTORS OF DIS: 2 24 3 16 4 12 6 8
"AC" AT 111 REP AT 161, DIS 50, FACTORS OF DIS: 2 25 5 10
"EB" AT 113 REP AT 130, DIS 17, FACTORS OF DIS:
"BK" AT 114 REP AT 128, DIS 14, FACTORS OF DIS: 2 7
"DE" AT 120 REP AT 122, DIS 2, FACTORS OF DIS:
"ED" AT 121 REP AT 136, DIS 15, FACTORS OF DIS: 3 5
"HE" AT 145 REP AT 167, DIS 22, FACTORS OF DIS: 2 11
"AC" AT 153 REP AT 159, DIS 6, FACTORS OF DIS: 2 3
"AC" AT 153 REP AT 161, DIS 8, FACTORS OF DIS: 2 4
"CA" AT 158 REP AT 160, DIS 2, FACTORS OF DIS:
"AC" AT 159 REP AT 161, DIS 2, FACTORS OF DIS:
"HO" AT 171 REP AT 175, DIS 4, FACTORS OF DIS: 2 2
"CGA" AT 21 REP AT 83, DIS 62, FACTORS OF DIS: 2 31
"EHJ" AT 90 REP AT 141, DIS 51, FACTORS OF DIS: 3 17
*FACTOR OCCURENCES*
2 OCCURS 40 TIMES
3 OCCURS 20 TIMES
4 OCCURS 15 TIMES
5 OCCURS 14 TIMES
6 OCCURS 9 TIMES
8 OCCURS 7 TIMES
7 OCCURS 6 TIMES
10 OCCURS 6 TIMES
17 OCCURS 5 TIMES
14 OCCURS 4 TIMES
16 OCCURS 4 TIMES
11 OCCURS 4 TIMES
31 OCCURS 4 TIMES
13 OCCURS 3 TIMES
12 OCCURS 3 TIMES
15 OCCURS 3 TIMES
21 OCCURS 2 TIMES
23 OCCURS 2 TIMES
25 OCCURS 2 TIMES
28 OCCURS 2 TIMES
30 OCCURS 2 TIMES
9 OCCURS 2 TIMES
32 OCCURS 2 TIMES
41 OCCURS 2 TIMES
43 OCCURS 2 TIMES
46 OCCURS 2 TIMES
47 OCCURS 2 TIMES
64 OCCURS 2 TIMES
24 OCCURS 1 TIMES
34 OCCURS 1 TIMES
37 OCCURS 1 TIMES
20 OCCURS 1 TIMES
42 OCCURS 1 TIMES
26 OCCURS 1 TIMES
44 OCCURS 1 TIMES
45 OCCURS 1 TIMES
18 OCCURS 1 TIMES
22 OCCURS 1 TIMES
53 OCCURS 1 TIMES
59 OCCURS 1 TIMES
61 OCCURS 1 TIMES
19 OCCURS 1 TIMES
65 OCCURS 1 TIMES
68 OCCURS 1 TIMES
69 OCCURS 1 TIMES
82 OCCURS 1 TIMES
86 OCCURS 1 TIMES