-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy path059_oxr_decryption.rb
100 lines (86 loc) · 7.59 KB
/
059_oxr_decryption.rb
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
# Each character on a computer is assigned a unique code and the preferred standard is ASCII
# (American Standard Code for Information Interchange). For example, uppercase A = 65,
# asterisk (*) = 42, and lowercase k = 107.
# A modern encryption method is to take a text file, convert the bytes to ASCII, then XOR each byte
# with a given value, taken from a secret key. The advantage with the XOR function is that using the
# same encryption key on the cipher text, restores the plain text; for example, 65 XOR 42 = 107, then
# 107 XOR 42 = 65.
# For unbreakable encryption, the key is the same length as the plain text message, and the key is
# made up of random bytes. The user would keep the encrypted message and the encryption key in
# different locations, and without both "halves", it is impossible to decrypt the message.
# Unfortunately, this method is impractical for most users, so the modified method is to use a
# password as a key. If the password is shorter than the message, which is likely, the key is
# repeated cyclically throughout the message. The balance for this method is using a sufficiently
# long password key for security, but short enough to be memorable.
# Your task has been made easy, as the encryption key consists of three lower case characters.
# Using cipher.txt (copied below), a file containing the encrypted
# ASCII codes, and the knowledge that the plain text must contain common English words, decrypt
# the message and find the sum of the ASCII values in the original text.
message = [79,59,12,2,79,35,8,28,20,2,3,68,8,9,68,45,0,12,9,67,68,4,7,5,23,27,1,21,79,85,78,79,85,71,38,10,71,27,12,2,79,6,2,8,13,9,1,13,9,8,68,19,7,1,71,56,11,21,11,68,6,3,22,2,14,0,30,79,1,31,6,23,19,10,0,73,79,44,2,79,19,6,28,68,16,6,16,15,79,35,8,11,72,71,14,10,3,79,12,2,79,19,6,28,68,32,0,0,73,79,86,71,39,1,71,24,5,20,79,13,9,79,16,15,10,68,5,10,3,14,1,10,14,1,3,71,24,13,19,7,68,32,0,0,73,79,87,71,39,1,71,12,22,2,14,16,2,11,68,2,25,1,21,22,16,15,6,10,0,79,16,15,10,22,2,79,13,20,65,68,41,0,16,15,6,10,0,79,1,31,6,23,19,28,68,19,7,5,19,79,12,2,79,0,14,11,10,64,27,68,10,14,15,2,65,68,83,79,40,14,9,1,71,6,16,20,10,8,1,79,19,6,28,68,14,1,68,15,6,9,75,79,5,9,11,68,19,7,13,20,79,8,14,9,1,71,8,13,17,10,23,71,3,13,0,7,16,71,27,11,71,10,18,2,29,29,8,1,1,73,79,81,71,59,12,2,79,8,14,8,12,19,79,23,15,6,10,2,28,68,19,7,22,8,26,3,15,79,16,15,10,68,3,14,22,12,1,1,20,28,72,71,14,10,3,79,16,15,10,68,3,14,22,12,1,1,20,28,68,4,14,10,71,1,1,17,10,22,71,10,28,19,6,10,0,26,13,20,7,68,14,27,74,71,89,68,32,0,0,71,28,1,9,27,68,45,0,12,9,79,16,15,10,68,37,14,20,19,6,23,19,79,83,71,27,11,71,27,1,11,3,68,2,25,1,21,22,11,9,10,68,6,13,11,18,27,68,19,7,1,71,3,13,0,7,16,71,28,11,71,27,12,6,27,68,2,25,1,21,22,11,9,10,68,10,6,3,15,27,68,5,10,8,14,10,18,2,79,6,2,12,5,18,28,1,71,0,2,71,7,13,20,79,16,2,28,16,14,2,11,9,22,74,71,87,68,45,0,12,9,79,12,14,2,23,2,3,2,71,24,5,20,79,10,8,27,68,19,7,1,71,3,13,0,7,16,92,79,12,2,79,19,6,28,68,8,1,8,30,79,5,71,24,13,19,1,1,20,28,68,19,0,68,19,7,1,71,3,13,0,7,16,73,79,93,71,59,12,2,79,11,9,10,68,16,7,11,71,6,23,71,27,12,2,79,16,21,26,1,71,3,13,0,7,16,75,79,19,15,0,68,0,6,18,2,28,68,11,6,3,15,27,68,19,0,68,2,25,1,21,22,11,9,10,72,71,24,5,20,79,3,8,6,10,0,79,16,8,79,7,8,2,1,71,6,10,19,0,68,19,7,1,71,24,11,21,3,0,73,79,85,87,79,38,18,27,68,6,3,16,15,0,17,0,7,68,19,7,1,71,24,11,21,3,0,71,24,5,20,79,9,6,11,1,71,27,12,21,0,17,0,7,68,15,6,9,75,79,16,15,10,68,16,0,22,11,11,68,3,6,0,9,72,16,71,29,1,4,0,3,9,6,30,2,79,12,14,2,68,16,7,1,9,79,12,2,79,7,6,2,1,73,79,85,86,79,33,17,10,10,71,6,10,71,7,13,20,79,11,16,1,68,11,14,10,3,79,5,9,11,68,6,2,11,9,8,68,15,6,23,71,0,19,9,79,20,2,0,20,11,10,72,71,7,1,71,24,5,20,79,10,8,27,68,6,12,7,2,31,16,2,11,74,71,94,86,71,45,17,19,79,16,8,79,5,11,3,68,16,7,11,71,13,1,11,6,1,17,10,0,71,7,13,10,79,5,9,11,68,6,12,7,2,31,16,2,11,68,15,6,9,75,79,12,2,79,3,6,25,1,71,27,12,2,79,22,14,8,12,19,79,16,8,79,6,2,12,11,10,10,68,4,7,13,11,11,22,2,1,68,8,9,68,32,0,0,73,79,85,84,79,48,15,10,29,71,14,22,2,79,22,2,13,11,21,1,69,71,59,12,14,28,68,14,28,68,9,0,16,71,14,68,23,7,29,20,6,7,6,3,68,5,6,22,19,7,68,21,10,23,18,3,16,14,1,3,71,9,22,8,2,68,15,26,9,6,1,68,23,14,23,20,6,11,9,79,11,21,79,20,11,14,10,75,79,16,15,6,23,71,29,1,5,6,22,19,7,68,4,0,9,2,28,68,1,29,11,10,79,35,8,11,74,86,91,68,52,0,68,19,7,1,71,56,11,21,11,68,5,10,7,6,2,1,71,7,17,10,14,10,71,14,10,3,79,8,14,25,1,3,79,12,2,29,1,71,0,10,71,10,5,21,27,12,71,14,9,8,1,3,71,26,23,73,79,44,2,79,19,6,28,68,1,26,8,11,79,11,1,79,17,9,9,5,14,3,13,9,8,68,11,0,18,2,79,5,9,11,68,1,14,13,19,7,2,18,3,10,2,28,23,73,79,37,9,11,68,16,10,68,15,14,18,2,79,23,2,10,10,71,7,13,20,79,3,11,0,22,30,67,68,19,7,1,71,8,8,8,29,29,71,0,2,71,27,12,2,79,11,9,3,29,71,60,11,9,79,11,1,79,16,15,10,68,33,14,16,15,10,22,73]
message_hash = {}
message.each do |number|
message_hash[number] ||= 0
message_hash[number] += 1
end
puts message_hash
decrypt_hash = {}
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = " "
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "e"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "t"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "a"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "o"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "i"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "n"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "s"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "r"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "h"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "l"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "d"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "c"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "u"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "m"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "f"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "p"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "g"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "w"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "y"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "b"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "v"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "k"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "x"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "j"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "q"
message_hash[message_hash.max_by{|k,v| v}[0]] = 0
decrypt_hash[message_hash.max_by{|k,v| v}[0]] = "z"
decoded_message = []
puts message_hash
message.each do |number|
decoded_message << decrypt_hash[number]
end
puts decoded_message.join("")
puts message_hash.keys.length