Want To Test A Test No-one Has Ever Taken, or Every Will Again?
Want To Test A Test No-one Has Ever Taken, or Ever Will Again?
I love creating academic challenges which are forever changing, and where the challenge is forever challenging. For this we can create the same set of challenges but vary the content. So, I’ve developed a cipher challenge created, which will generate a unique challenge each time [link]:
Additional information: a (%61) b (%62) c (%63) d (%64) e (%65) f (%66) g (%67) h (%68) i (%69) j (%6A) k (%6B) l (%6C)…asecuritysite.com
I’ve done the calculations, and it is almost impossible to ever get the same set of questions, for each instance created.
I’ve set it up so that a teacher can copy and paste the challenge questions into a worksheeet, and include the answer (which would be taken out, of course). If I generate one, here’s what we get:
Q. For the following cipher (ASCII coding), determine the decoded string: %65%6D%75%6C%61%74%6F%72
Additional information:
a (%61) b (%62) c (%63) d (%64) e (%65) f (%66) g (%67) h (%68) i (%69) j (%6A) k (%6B)
l (%6C) m (%6D) n (%6E) o (%6F) p (%70) q (%71) r (%72) s (%73) t (%74) u (%75) v (%76)
w (%77) x (%78) y (%79) z (%80) SPACE (%20)
Ans: emulator
Q. What is the plain text for the following Bacon cipher: AABBA AABAA ABBAB ABABB AABAA BAABA BAAAA BABBA
Additional information:
a AAAAA g AABBA n ABBAA t BAABA
b AAAAB h AABBB o ABBAB u-v BAABB
c AAABA i-j ABAAA p ABBBA w BABAA
d AAABB k ABAAB q ABBBB x BABAB
e AABAA l ABABA r BAAAA y BABBA
f AABAB m ABABB s BAAAB z BABBB
Ans: geometry
Q. What is the plain text for the following Polybius cipher: 15 33 51 32 11 45 35 43
Additional information:
12345
------
1-ABCDE
2-FGHIJ
3-KLMNO
4-PQRST
5-UVWXY
Ans: emulator
Q. What is the plain text for the Dvorak cipher of: UCP.
Additional information:
Plain: abcdefghijklmnopqrstuvwxyz
Cipher: axje.uidchtnmbrl'poygk,qf;
Ans: fire
Q. What is the Atbash cipher for the word: VTT
Additional information:
Plain: abcdefghijklmnopqrstuvwxyz
Cipher: ZYXWVUTSRQPONMLKJIHGFEDCBA
Ans: egg
Q. What is the plain text for the Rot13 cipher of: SBEJNEQ
Additional information:
Plain: abcdefghijklmnopqrstuvwxyz
Cipher: NOPQRSTUVWXYZABCDEFGHIJKLM
Ans: forward
Q. With a Caeser cipher, if we use either a 1 letter, 2 letter or 3 letter shift (as defined below), which is the plaintext for: EFONBSL
Additional information:
For a 1 letter shift:
abcdefghijklmnopqrstuvwxyz
BCDEFGHIJKLMNOPQRSTUVWXYZA
for two shifts:
abcdefghijklmnopqrstuvwxyz
CDEFGHIJKLMNOPQRSTUVWXYZAB
and three shifts:
abcdefghijklmnopqrstuvwxyz
DEFGHIJKLMNOPQRSTUVWXYZABC
Ans: denmark
Q. For the scrambled alphabet given below, which is the plaintext for the cipher of: VBERTE
Additional information:
Plain: abcdefghijklmnopqrstuvwxyz
Cipher: VNDILZKPRHWQFUCOSBTEGXAYJM
Ans: artist
Q. For the following Morse code, what is the plaintext: (···) ( — · — ·) ( — — — ) ( — ) (· — ··) (· — ) ( — ·) ( — ··)
Additional information:
A(·—) B(—···
C(—·—·) D(—··)
E(·) F(··—·)
G(— —·) G(····)
I(··) J(·— — —)
K(—·—) L(·—··)
M(— —) N(—·)
O(— — —) P(·— —·)
Q(— —·—) R(·—·)
S(···) T(—)
U(··—) V(···—)
W(·— —) X(—··—)
Y(—·— — Z(— —··)
Ans: scotland
Q. A homomorphic cipher uses several codes for each plaintext character. For the homomorphic cipher given below, which is the plaintext for the cipher of: 78 39 82 79
Additional information:
a b c d e f g h i j k l m n o p q r s t u v w x y z
07 11 17 10 25 08 44 19 02 18 41 42 40 00 16 01 15 04 06 05 13 22 45 12 55 47
31 64 33 27 26 09 83 20 03 81 52 43 30 62 24 34 23 14 46 93
50 49 51 28 21 29 86 80 61 39 56 35 36
63 76 32 54 53 95 88 65 58 57 37
66 48 70 68 89 91 71 59 38
77 67 87 73 94 00 90 60
84 69 96 74
72 78
75 92
79
82
85
Ans: tree
Q. For the keyword cipher, for a cipher word (and key word of “ANKLE”) determine the plaintext: aiifcator
Additional information:
The following uses a keyword of Krytos, and a message of "knowledgeispower": Here, and it should give DGHVETPSTBMIHVTL.
Plaintext: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Encrypted: K R Y P T O S A B C D E F G H I J L M N Q U V W X Z
With KRYPTOS as the keyword, all As become Ks, all Bs become Rs and so on. Encrypting the message "knowledge is power" using the keyword "kryptos":
Plaintext: K N O W L E D G E I S P O W E R
Encoded: D G H V E T P S T B M I H V T L
Ans: alligator
Q. For the Bifid cipher, for a cipher word of the following determine the plaintext: zooys
Additional information:
First we start with a grid:
1 2 3 4 5
1 B G W K Z
2 Q P N D S
3 I O A X E
4 F C L U M
5 T H Y V R
Next we look up the grid, and the arrange the two character values into two rows. For example is we have a plaintext of "marylan", then "m" is "4" and "5", so we place "4" in the first row, and "5" in the second row, and continue to do this for all the letters:
maryland
43554322
53533334
Next we read along the rows and merge, to give:
43 55 43 22 53 53 33 34
Next we convert them back to letters from the grid:
L R L P Y Y A X
Let’s try the reverse, with DXETE. For we look up the grid to get:
24 34 35 51 35
We can then put then into rows to give:
2 4 3 4 3
5 5 1 3 5
This gives us 25 (s) 45 (m), 31 (i) 43 (l) 35 (e) – which is smile.
Ans: grape
Q. For the following Straddling cipher, what is the plain text: 28 4 5 22 4 5
Additional information:
0 1 2 3 4 5 6 7 8 9
E T A O N R I S
2 B C D F G H J K L M
6 P Q / U V W X Y Z .
Ans: london
Q. For the follow cipher, we use a 3-rail code (an example given below). Which is the plaintext for the following 3-rail cipher code: BBAKO ECN
Additional information:
'WE ARE DISCOVERED. FLEE AT ONCE', gives:
W . . . E . . . C . . . R . . . L . . . T . . . E
. E . R . D . S . O . E . E . F . E . A . O . C .
. . A . . . I . . . V . . . D . . . E . . . N . .
to give:
WECRL TEERD SOEEF EAOCA IVDEN
Ans: backbone
Q. The Pollux cipher, we use Morse code (see below) to determine a code (see below). Which is the plaintext for the following Pollux cipher: 761897082410420898288167879
Additional information:
To determine a code, and then map a dot, dash or seperator with the following:
Dot - 0, 7 or
Dash - 1, 8 or 5
Seperator - 2, 9, 6 or 3
If we take a code of "784067897459184640779", we can determine the following:
784067897459184640779
.-.. .- ..- --. ....
L A U G H
For example "GE" becomes "— — ·" and "·", so we can then encode to 180 2 7 9 to give 180279.
Morse code:
A(·—)
B(—···
C(—·—·)
D(—··)
E(·)
F(··—·)
G(— —·)
H(····)
I(··)
J(·— — —)
K(—·—)
L(·—··)
M(— —)
N(—·)
O(— — —)
P(·— —·)
Q(— —·—)
R(·—·)
S(···)
T(—)
U(··—)
V(···—)
W(·— —)
X(—··—)
Y(—·— —
Z(— —··)
Ans: emulator
Q. The following Fractional cipher (see below), determine the plaintext: JGQDWQI
Additional information:
"Hello World" is Morse Code is:
.... . .-.. .-.. --- / .-- --- .-. .-.. -..
H E L L O SPACE W O R L D
We can then make this into a string with an 'x' between characters:
Plain text: H e l l o w o r l d
Morse string: ....x.x.-..x.-..x---xx.--x---x.-.x.-..x-..
We can now use three-character mappings to convert them back to text:
['...', '..-', '..x', '.-.', '.--', '.-x', '.x.', '.x-', '.xx', '-..', '-.-', '-.x', '--.', '---', '--x', '-x.', '-x-','-xx', 'x..', 'x.-', 'x.x', 'x-.', 'x--', 'x-x', 'xx.', 'xx-']
This mapping is:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
. . . . . . . . . - - - - - - - - - x x x x x x x x
. . . - - - x x x . . . - - - x x x . . . - - - x x
. - x . - x . - x . - x . - x . - x . - x . - x . -
which will map to "ABCDEF...Z". Next we can convert them back with:
AGTCDHOTQODTCJ
For "Peter piper picked " we get:
.--.x.x-x.x.-.xx.--.x..x.--.x.x.-.xx.--.x..x-.-.x-.-x.x-..xx
P e t e r ' ' p i p e r' ' p i c k e d ' '
Standard Morse code
E . S ... H .... B -... 1 .---- period .-.-.-
T - U ..- V ...- X-..- 2 ..--- comma --..--
I .. R .-. F ..-. C-.-. 3 ...-- query .-.-.-
A .- W .-- L .-.. Y --.- 4 ....- colon ---...
N -. D -.. P .--. Z --.. 5 ..... s/colon -.-.-.
M -- K -.- J .--- Q --.- 6 -.... dash -....-
G --. 7 --... slash -..-.
O --- 8 ---.. equals -...-
9 ----.
0 -----
Ans: bacon
Q. For the following jump cipher with jump of 4 (see below), what is the plaintext: nmiagrhet (Jump: 5)
Additional information:
If we have a skip of 3, then:
The social network said its members had expressed concerns that they were missing 'important updates' from the people they cared about.
becomes:
T cleo ii mrh psdoesh eweii mrnuasfmhpp eceauT cleo ii mrh psdoesh eweii mrnuasfmhpp eceauT cleo ii mrh psdoesh eweii mrnuasfmhpp eceau
For example if we have plain text of "01234567", with a jump of 3 we get:
03614725
Now we take "epnlhtea", and match:
03614725
epnlhtea
Let's take the first three charactersof 0, 1 and 2, which are e, l and e:
eleXXXX
Next 3, 4 and 5, which are p, h and a:
elephaXX
Finally for 6 and 6, which are n and t
elephant
Ans: nightmare
Q. What is the Affine cipher for the word: technique [a=3, b=8]
Additional information:
https://asecuritysite.com/challenges/affine
Ans: nuodvgequ
Q. What is the Vigenère cipher (see below) using a key of “KING” for the word: fish
Additional information:
The great advantage of this type of code is that the same plaintext character will be encrypted with different values, depending on the position of the keyword. For example, if the keyword is GREEN, ‘e’ can be encrypted as ‘K’ (for G), ‘V’ (for R), ‘I’ (for E) and ‘R’ (for N). To improve the security, the greater the size of the code word, the more the rows that can be included in the encryption process. Also, it is not possible to decipher the code by a frequency analysis, as letters will change their coding depending on the current position of the keyword. It is also safe from analysis of common two- and three-letter occurrences, if the keysize is relatively long. For example ‘ee’ could be encrypted with ‘KV’ (for GR), ‘VI’ (for RE), ‘II’ (for EE), ‘IR’ (for EN) and ‘RK’ (for NG).
Plain a b c d e f g h i j k l m n o p q r s t u v w x y z
1 b c d e f g h i j k l m n o p q r s t u v w x y z a
2 c d e f g h i j k l m n o p q r s t u v w x y z a b
3 d e f g h i j k l m n o p q r s t u v w x y z a b c
4 e f g h i j k l m n o p q r s t u v w x y z a b c d
5 f g h i j k l m n o p q r s t u v w x y z a b c d e
6 g h i j k l m n o p q r s t u v w x y z a b c d e f
7 h i j k l m n o p q r s t u v w x y z a b c d e f g
8 i j k l m n o p q r s t u v w x y z a b c d e f g h
9 j k l m n o p q r s t u v w x y z a b c d e f g h i
10 k l m n o p q r s t u v w x y z a b c d e f g h i j
11 l m n o p q r s t u v w x y z a b c d e f g h i j k
12 m n o p q r s t u v w x y z a b c d e f g h i j k l
13 n o p q r s t u v w x y z a b c d e f g h i j k l m
14 o p q r s t u v w x y z a b c d e f g h i j k l m n
15 p q r s t u v w x y z a b c d e f g h i j k l m n o
16 q r s t u v w x y z a b c d e f g h i j k l m n o p
17 r s t u v w x y z a b c d e f g h i j k l m n o p q
18 s t u v w x y z a b c d e f g h i j k l m n o p q r
19 t u v w x y z a b c d e f g h i j k l m n o p q r s
20 u v w x y z a b c d e f g h i j k l m n o p q r s t
21 v w x y z a b c d e f g h i j k l m n o p q r s t u
22 w x y z a b c d e f g h i j k l m n o p q r s t u v
23 x y z a b c d e f g h i j k l m n o p q r s t u v w
24 y z a b c d e f g h i j k l m n o p q r s t u v w x
25 z a b c d e f g h i j k l m n o p q r s t u v w x y
Ans: pqfn
Q. What is the Beauford cipher for the word: technique [Key: apple]
Additional information:
https://asecuritysite.com/coding/beau
Ans: hlnerszvh
Q. The Navajo cipher table is given below. What is the plaintext for this: Dibeh-yazzi Dzeh Klizzie
Additional information:
Alphabets (English) Code Language (English) Code Language (Navajo)
A Ant Wol-la-chee
B Bear Shush
C Cat Moashi
D Deer Be
E Elk Dzeh
F Fox Ma-e
G Goat Klizzie
H Horse Lin
I Ice Tkin
J Jackass Tkele-cho-gi
K Kid Klizzie-yazzi
L Lamb Dibeh-yazzi
M Mouse Na-as-tso-si
N Nut Nesh-chee
O Owl Ne-ash-jsn
P Pig Bi-sodih
Q Quiver Ca-yeilth
R Rabbit Gah
S Sheep Dibeh
T Turkey Than-zie
U Ute No-da-ih
V Victor a-keh-di-glini
W Weasel Gloe-ih
X Cross Al-an-as-dzoh
Y Yucca Tsah-as-zih
Z Zinc Besh-do-gliz
Ans: leg
Conclusions
Ciphers are fun, and great for your brain. Go and crack some. Here’s the on-line version: