Make .txt file unreadable / uneditable

Question

I have a program which saves a little .txt file with a highscore in it:

 // Create a file to write to. 
string createHighscore = _higscore + Environment.NewL         


        

Answer 1

You can serialize it and deserialize with encryption with CryptoStream :

Serialize file :

• Create and open FileStream in write mode
• Create Cryptostream and pass your filestream
• Write contents to Cryptostream (encrypt)

Deserialize file :

• Create and open FileStream in read mode
• Create Cryptostream and pass your filestream
• Read from Cryptostream (decrypt)

You can find examples and more information here :

msdn.microsoft.com/en-us/library/system.security.cryptography.cryptostream.aspx

http://www.codeproject.com/Articles/6465/Using-CryptoStream-in-C

Example :

byte[] key = { 1, 2, 3, 4, 5, 6, 7, 8 }; // Where to store these keys is the tricky part, 
byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };
string path = @"C:\path\to.file";

DESCryptoServiceProvider des = new DESCryptoServiceProvider();

// Encryption and serialization
using (var fStream = new FileStream(path, FileMode.Create, FileAccess.Write))
using (var cryptoStream = new CryptoStream(fStream , des.CreateEncryptor(key, iv), CryptoStreamMode.Write))
{
    BinaryFormatter serializer = new BinaryFormatter();

    // This is where you serialize your data
    serializer.Serialize(cryptoStream, yourData);
}



// Decryption
using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read))
using (var cryptoStream = new CryptoStream(fs, des.CreateDecryptor(key, iv), CryptoStreamMode.Read))
{
    BinaryFormatter serializer = new BinaryFormatter();

    // Deserialize your data from file
    yourDataType yourData = (yourDataType)serializer.Deserialize(cryptoStream);
}