/* -------------------------------------------------------------
Encryption Process of HFE Encryption Scheme
loads public key from public_key.txt and encrypts a random message
ciphertext is stored in ciphertext.txt
---------------------------------------------------------------*/
clear ;

SetSeed(0,0);
printf "****************************************** \n";
printf "*** HFE Encryption Scheme - Encryption *** \n";
printf "****************************************** \n \n";

timet:= Cputime();

load "public_key.txt";

message:=Random(messagespace);

printf"message:= %o\n\n", message;

for i:=1 to n do
	for j:=1 to n do
	Pk[i]:=Evaluate(Pk[i],Pol.j,message[j]);
	end for;
end for;
ciphertext:=messagespace!(Pk);
printf "time for encryption: %o\n\n",Cputime(timet);

printf"ciphertext:= %o \n\n", ciphertext;


printf"Write ciphertext.txt \n\n";
SetOutputFile("ciphertext.txt":Overwrite:=true);
printf "ciphertext:= %o ;\n\n", Eltseq(ciphertext);
printf "original := %o;\n",Eltseq(message) ;
UnsetOutputFile();