Marian Dan Alexandru

For generating a random password containing hex  digits one can use:

hexdump -n32 -e '"%x"' /dev/random

where 32 is the length of the string, and the format is ‘”%x”.

Use case scenario:

1. Compile the module
1> c(cipher).
1. {ok,last}
2. Use it:
2> cipher:substitutionCipher(“dan”,[100,97,110],[97,100,110]).
1. "adn"
3. Source code:
-module(cipher).
1. -export([substitutionCipher/3]).
2.  
3. makeTranslation([],[],L)->L;
4. makeTranslation([X|Xs],[Y|Ys],L)->makeTranslation(Xs,Ys,[{X,Y}|L]).
5. makeTranslation(OriginalAlphabet,CryptedAlphabet)->makeTranslation(OriginalAlphabet,CryptedAlphabet,[]).
6.  
7. getTranslation(E,[{X,Y}|Tail])->
8.  case E==X of
9.    true -> Y;
10.    false-> getTranslation(E,Tail)
11.  end;
12. getTranslation(_,[])->false.
13.  
14. substitute([],_,Substitution)->lists:reverse(Substitution);
15. substitute([H|RestOfMessage],Translation,Substitution)->
16. substitute(RestOfMessage,Translation,[getTranslation(H,Translation)]++Substitution).
17.  
18. substitutionCipher(Message,OriginalAlphabet,CryptedAlphabet)-> Translation = makeTranslation(OriginalAlphabet,CryptedAlphabet), substitute(Message,Translation,[]).