标题：加密和解密的密匙问题

EncryptText函数加密的字符串可以用函数DecryptText解密，解密和加密的密钥必须相同。这一句话怎么理解。

如果要实现： 

加密后的文件。直接用ReadAllText调入并赋值到变量中，并使用事前“文件加密的密钥”进行解密还原，这一块怎么操作？

Dim Val1 As String = FileSys.ReadAllTExt("c:\data\abc.txt")
Dim Val2 As String = DecryptText(Val1,"密匙1","密匙2")

这一段代码该如何修改

EncryptFile("c:\11.txt", "c:\22.txt", "fox123")
Dim Val1 As String = FileSys.ReadAllTExt("c:\22.txt")
Dim Val2 As String = DecryptText(Val1,"fox123")  　　　' 无密钥2
Output.Show("解密后:" & val2)

 

加密：
 
Dim Val1 As String = FileSys.ReadAllTExt("c:\123.txt")
Dim Val2 As String = EncryptText(Val1,"密匙1","密匙2") 
Filsys.WriteAllText("c:\123.txt",val2)

解密：
 
Dim Val1 As String = FileSys.ReadAllTExt("c:\123.txt")
Dim Val2 As String = DecryptText(Val1,"密匙1","密匙2") 
Filsys.WriteAllText("c:\123.txt",val2)