You are developing a method to encrypt sensitive data with the Data Encryption Standard (DES)
algorithm. Your method accepts the following parameters:
The byte array to be encrypted, which is named messageAn encryption key, which is named
keyAn initialization vector, which is named iv
You need to encrypt the data. You also need to write the encrypted data to a MemoryStream
object.
Which code segment should you use?
A. DES^ des = gcnew DESCryptoServiceProvider();
des->BlockSize = message->Length;
ICryptoTransform^ crypto = des->CreateEncryptor(key, iv);
MemoryStream ^cipherStream = gcnew MemoryStream();
CryptoStream ^cryptoStream = gcnew CryptoStream(cipherStream,crypto,
CryptoStreamMode::Write);
cryptoStream->Write(message, 0, message->Length);
B. DES^ des = gcnew DESCryptoServiceProvider();
ICryptoTransform^ crypto = des->CreateDecryptor(key, iv);
MemoryStream ^cipherStream = gcnew MemoryStream();
CryptoStream ^cryptoStream = gcnew CryptoStream(cipherStream, crypto,
CryptoStreamMode::Write);
cryptoStream->Write(message, 0, message->Length);
C. DES^ des = gcnew DESCryptoServiceProvider();ICryptoTransform^ crypto = des-
>CreateDecryptor();
MemoryStream ^cipherStream = gcnew MemoryStream();CryptoStream ^cryptoStream
= gcnew CryptoStream(cipherStream,crypto,
CryptoStreamMode::Write);cryptoStream->Write(message, 0, message->Length);
D. DES^ des = gcnew DESCryptoServiceProvider();ICryptoTransform^ crypto = des-
>CreateEncryptor(key, iv);
MemoryStream ^cipherStream = gcnew MemoryStream();CryptoStream ^cryptoStream
= gcnew CryptoStream(cipherStream, crypto, CryptoStreamMode::Write);
cryptoStream->Write(message, 0, message->Length);
Answer: D
algorithm. Your method accepts the following parameters:
The byte array to be encrypted, which is named messageAn encryption key, which is named
keyAn initialization vector, which is named iv
You need to encrypt the data. You also need to write the encrypted data to a MemoryStream
object.
Which code segment should you use?
A. DES^ des = gcnew DESCryptoServiceProvider();
des->BlockSize = message->Length;
ICryptoTransform^ crypto = des->CreateEncryptor(key, iv);
MemoryStream ^cipherStream = gcnew MemoryStream();
CryptoStream ^cryptoStream = gcnew CryptoStream(cipherStream,crypto,
CryptoStreamMode::Write);
cryptoStream->Write(message, 0, message->Length);
B. DES^ des = gcnew DESCryptoServiceProvider();
ICryptoTransform^ crypto = des->CreateDecryptor(key, iv);
MemoryStream ^cipherStream = gcnew MemoryStream();
CryptoStream ^cryptoStream = gcnew CryptoStream(cipherStream, crypto,
CryptoStreamMode::Write);
cryptoStream->Write(message, 0, message->Length);
C. DES^ des = gcnew DESCryptoServiceProvider();ICryptoTransform^ crypto = des-
>CreateDecryptor();
MemoryStream ^cipherStream = gcnew MemoryStream();CryptoStream ^cryptoStream
= gcnew CryptoStream(cipherStream,crypto,
CryptoStreamMode::Write);cryptoStream->Write(message, 0, message->Length);
D. DES^ des = gcnew DESCryptoServiceProvider();ICryptoTransform^ crypto = des-
>CreateEncryptor(key, iv);
MemoryStream ^cipherStream = gcnew MemoryStream();CryptoStream ^cryptoStream
= gcnew CryptoStream(cipherStream, crypto, CryptoStreamMode::Write);
cryptoStream->Write(message, 0, message->Length);
Answer: D
When I first read all the four options I was completely confused. And to clear my doubt I just used each of the code segment to check which one is the correct solution and yes the last option is the right solution to perform this task.
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