一个很简单的加密算法

当时见到一张帖子即兴写了这段代码,还没认真调试过

program Project1;

{$APPTYPE CONSOLE}

uses

SysUtils;

const

Key='TESTNET';

Cryptograph='有些事还是不知为妙';

//不能为0.5,相加为1

Percent1=0.21;

Percent2=0.79;

var

s1:string;

function GetKey(aKey:string;aPercent:Double):string;

var

i:integer;

begin

SetLength(Result,Length(aKey));

for i:=1 to Length(aKey) do

begin

Result[i]:=Chr(Round(Ord(aKey[i])*aPercent));

end;

end;

function EnCode(aCryptograph,aKey:string):string;

var

i,keylen,codelen:integer;

begin

keylen:=Length(akey);

codelen:=Length(aCryptograph);

SetLength(Result, Length(aCryptograph));

for i:=1 to codelen do

begin

Result[i]:=Chr(Ord(aCryptograph[i])+Ord(aKey[(i mod KeyLen)+1]));

end;

end;

function DeCode(aCryptograph,aKey:string):string;

var

i,keylen,codelen:integer;

begin

keylen:=Length(akey);

codelen:=Length(aCryptograph);

SetLength(Result, Length(aCryptograph));

for i:=1 to codelen do

begin

Result[i]:=Chr(Ord(aCryptograph[i])-Ord(aKey[(i mod KeyLen)+1]));

end;

end;

begin

{ TODO -oUser -cConsole Main : Insert code here }

WriteLn('要加密的文字');

WriteLn(Cryptograph);

WriteLn;

WriteLn('密码经过第一个网络');

s1:=EnCode(Cryptograph,GetKey(Key,Percent1));

WriteLn(s1);

WriteLn;

WriteLn('密码经过第二个网络');

s1:=EnCode(s1,GetKey(Key,Percent2));

WriteLn(s1);

WriteLn;

WriteLn('还原');

s1:=DeCode(s1,Key);

WriteLn(s1);

WriteLn;

WriteLn('如果要在VCL控件中显示，还要对#0进行处理,'+

'因为VCL中大部分函数以#0作为结束标记');

ReadLn;

end.