How to Use Encryption Algorithms in Visual C++

It is fairly easy to use encryption algorithms in visual C++. The most common approach is to use public key encryption with a digital certificate. To accomplish this, all you need is to have access to the Chilkat C++ encryption algorithm library.

Difficulty: Moderately Challenging

Instructions

1. Determine if the Chilkat C++ algorithm is available on your Windows programming workstation. If it isn't, then go the World Wide Web to download it.

2. Open Visual C++ on your programming workstation and create a new file called encrypt.cpp.

3. Load the header files CkCrypt.2 and CkCert.h at the top of this file. This can be accomplished using the following syntax:
   #include
   #include

4. Create a void function called RunEncryption().

5. Initialize a new CkCrypt2 object. The syntax for this is:
   CkCrypt2 myEncrypt;

6. Establish public key encryption. Call this put_CryptAlgorithm with the following syntax:
   myEncrypt.put_CryptAlgorithm("pki");

7. Initialize a new Certificate object. Use the following syntax:
   CkCert myCertificate;

8. Load your digital certificate from a file. This can be done use the LoadFromFile function. We will assume that this certificate is called sample.cert.
   myCertificate.LoadFromFile("sample.cert");

9. Encrypt the file using the CkEncryptFile function. Assume that the data you want to encrypt is in the file named fileToEncrypt.txt. Use the following syntax:
   myEncrypt.CkEncryptFile("fileToEncrypt.txt");

10. Compile encrypt.cpp in Visual C++. If the compile is successful, execute this program to test it out.

Tips & Warnings

• If you have compilation errors, check for missing semicolons.
• Decrypting a file is easy using the CkDecryptFile function.
• Keep your digital certificate in a safe place. This is required for decrypting the file.