Encrypt/Decrypt APIs from Ncrypt.h header take long time to execute

Sudheendra Subbarao 6

We are trying to use Encrypt/Decrypt APIs from Ncrypt.h header.

To Encrypt, we use the below list of APIs

NCryptOpenStorageProvider
NCryptCreatePersistedKey
NCryptFinalizeKey
NCryptEncrypt
NCryptDecrypt

We see that 2 of the APIs namely NCryptFinalizeKey and NCryptDecrypt take a long time to execute nearly 1-2 seconds compared to other APIs which hardly take few milliseconds to execute.

Would like to know if this is the expected behaviour or we are missing anything here.
Any insight on this would be of real help

Nico Zhu (Shanghai Wicresoft Co,.Ltd.) 12,856 Reputation points

2022-06-29T02:31:07.057+00:00

NCryptOpenStorageProvider is win32 api, Do you develop win32 app or UWP app?
Sudheendra Subbarao 6 Reputation points

2022-06-29T05:08:59.117+00:00

We are calling the Win32 libraries from UWP using a Winrt Wrapper
so basically the APIs are in C++ library which are wrapped in Windows Runtime component. This WinRT component is then called by the UWP app.
Nico Zhu (Shanghai Wicresoft Co,.Ltd.) 12,856 Reputation points

2022-06-29T06:06:41.467+00:00

Does your app run in the release model ?
Sudheendra Subbarao 6 Reputation points

2022-06-29T07:15:01.337+00:00

Yes, release mode also its almost the same time .

Also we are using
NCryptOpenStorageProvider with MS_PLATFORM_CRYPTO_PROVIDER as we want to use with TPM
instead when we use MS_KEY_STORAGE_PROVIDER its pretty fast
Nico Zhu (Shanghai Wicresoft Co,.Ltd.) 12,856 Reputation points

2022-06-29T07:18:45.777+00:00

It's hard to explain, win32 Encrypt/Decrypt APIs may not very compatible with uwp. and if have the fast way, please feel free post your answer blow. I will vote it up.