Basic Examples

Try to decipher a string:
[◼]
CrackCaesarCipher
["Qeb nrfzh yoltk clu grjmp lsbo qeb ixwv ald"]
In[]:=
The quick brown fox jumps over the lazy dog
Out[]=

Scope

Give the top 5 deciphers of a short Caesar-enciphered message:
message=ResourceFunction["CaesarCipher"]["go on",11];​​
[◼]
CrackCaesarCipher
[message,5]
In[]:=
{DecipheredStringwe ed,Score4,Shift21,DecipheredStringgo on,Score4,Shift11,DecipheredStringtb ba,Score3,Shift24,DecipheredStringai ih,Score3,Shift17,DecipheredStringiq qp,Score3,Shift9}
Out[]=

Options

Method

Try to decipher the message using a dictionary attack:
s=ResourceFunction["CaesarCipher"]["the apple",11];​​
[◼]
CrackCaesarCipher
[s,Method"Dictionary"]
In[]:=
the apple
Out[]=
Try to decipher the message using a letter frequency attack :
[◼]
CrackCaesarCipher
[s,Method"LetterFrequency"]
In[]:=
iwt peeat
Out[]=

Language

Use another language:
ResourceFunction["CaesarCipher"]["Mijn naam is Sander!",11];​​
[◼]
CrackCaesarCipher
[%,Language->"Dutch"]
In[]:=
Mijn naam is Sander!
Out[]=

“WordValueFunction”

The default
"WordValueFunction"
is the length of the string:
s=ResourceFunction["CaesarCipher"]["The red car!",11];​​
[◼]
CrackCaesarCipher
[s,4,Method"Dictionary","WordValueFunction"StringLength]
In[]:=
{DecipheredStringThe red car!,Score14,Shift11,DecipheredStringNby lyx wul!,Score7,Shift17,DecipheredStringMax kxw vtk!,Score6,Shift18,DecipheredStringXli vih gev!,Score6,Shift7}
Out[]=
Value each matched string with a different metric. In this case just counting them:
s=ResourceFunction["CaesarCipher"]["The red car!",11];​​
[◼]
CrackCaesarCipher
[s,4,Method"Dictionary","WordValueFunction"(1&)]
In[]:=
{DecipheredStringXli vih gev!,Score4,Shift7,DecipheredStringNby lyx wul!,Score3,Shift17,DecipheredStringThe red car!,Score3,Shift11,DecipheredStringHvs fsr qof!,Score2,Shift23}
Out[]=

“DictionaryWords”

Give a custom dictionary in form of a list of strings. If in a piece of text certain words are expected this can speed up the cracking significantly:
s=ResourceFunction["CaesarCipher"]["my hovercraft is full of eels!",11];​​
[◼]
CrackCaesarCipher
[s,Method"Dictionary","DictionaryWords"{"airplane","truck","hovercraft","car","boat","plane","bike","bicyle","moped"}]
In[]:=
my hovercraft is full of eels!
Out[]=

Applications

Decipher a long text:
hamlet=ExampleData[{"Text","Hamlet"}];​​hamlet=ResourceFunction["CaesarCipher"][hamlet,6];​​
[◼]
CrackCaesarCipher
[hamlet]//Short
In[]:=
PERSONS REPRESENTED. Claudius, King of Denmark. Hamlet, Son to the former, and Ne…nt, bearing off the dead bodies; after the which a peal of ordnance is shot off.]
Out[]//Short=

Properties and Relations

The function
CrackCaesarCipher
can, like
CaesarDecipher
, undo a encipherment done by
CaesarCipher
:
message=ResourceFunction["CaesarCipher"]["This is a test",6];​​ResourceFunction["CaesarDecipher"][message,6],
[◼]
CrackCaesarCipher
[message]
In[]:=
{This is a test,This is a test}
Out[]=

Possible Issues

The setting for
Language
can change the outcome:
message=ResourceFunction["CaesarCipher"]["De rode auto!",11];​​
[◼]
CrackCaesarCipher
[message,Method"Dictionary",Language#]&/@{"Finnish","Dutch"}
In[]:=
The deciphered message with the highest score might not be the right one, in this case the second highest is the right deciphered message:
Long strings take very long to decipher using the Method “Dictionary”:
A frequency analysis is much faster: