CNG is slow?

Not quite sure why, but CNG (Cryptography-Next-Generation) is considerably slower than good old RSACryptoServiceProvider:

Method KeySize Mean Error StdDev
RSAEncrypt 512 7.304 μs 7.521 μs 0.4122 μs
RSADecrypt 512 31.200 μs 3.130 μs 0.1715 μs
RSACngEncrypt 512 142.589 μs 8.738 μs 0.4790 μs
RSACngDecrypt 512 184.463 μs 36.394 μs 1.9949 μs

There could be several reasons why CNG (Cryptography-Next-Generation) is slower than RSACryptoServiceProvider. Here are some possibilities:

  1. Algorithmic Differences: CNG uses different cryptographic algorithms than RSACryptoServiceProvider. Depending on the specific algorithms being used, CNG may be slower due to increased computational complexity or the need for additional calculations.
  2. Key Size: CNG may be using larger key sizes than RSACryptoServiceProvider, which can result in slower performance due to increased computational complexity.
  3. Hardware Acceleration: RSACryptoServiceProvider may be leveraging hardware acceleration, such as the Intel Advanced Encryption Standard (AES) instruction set, which can significantly speed up encryption and decryption operations. CNG may not be utilizing hardware acceleration to the same extent.
  4. Implementation Differences: The specific implementation of CNG or RSACryptoServiceProvider that you are using could be impacting performance. For example, if CNG is being used in a managed code environment such as C# or VB.NET, it may be slower due to the overhead of the .NET runtime.

It’s worth noting that while CNG may be slower than RSACryptoServiceProvider in certain scenarios, it is generally considered to be a more modern and secure encryption technology. Additionally, CNG offers other benefits such as support for elliptic curve cryptography and better performance on multi-core processors.

RSACryptoServiceProvider is a class in the .NET Framework that provides RSA encryption functionality.

Cryptography-Next-Generation (CNG) is a modern encryption technology introduced in Windows Vista that offers improved security and performance over previous cryptographic APIs.


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