I appreciate your help with this issue. I’m running a .NET 6.0 powered web and API application behind an Apache reverse proxy. These applications use some self-signed certificates for certain operations. Here’s the situation:

• Operating Systems: The application runs much faster on Ubuntu 20.04 LTS compared to Ubuntu 22.04 LTS and Ubuntu 24.04 LTS.
• Performance Investigation: We have identified that the cryptography operations in the application are slower on Ubuntu 22.04 LTS and Ubuntu 24.04 LTS.
• Expectation: Given that Ubuntu 22.04 LTS is a newer version, we expected it to be faster than Ubuntu 20.04 LTS.
• Hardware and Software Consistency: We are using the same hardware and software specifications across all versions (vCPU, RAM, HDD, etc.). There are no other background processes or applications running—just a fresh OS installation.

Any insights or suggestions on why cryptography operations might be slower on newer versions of Ubuntu would be greatly appreciated.
we use SHA 256 hashed self sign certificates

— Ubuntu 20.04 LTS —
Program Started!!!
Time taken to read the app config – 00:00:00.0000342
Time taken to deserialize app settings – 00:00:00.1070378

Time taken to generate random string – 00:00:00.0003254
Short Length Data Signing Started
Short Length Data Private Key to Object – 00:00:00.0301827
Short Length Data Public Key to Object – 00:00:00.0002089
Chain Info – True
Short Length Data Chain Build – 00:00:00.0530501
Short Length Data Base64 Conversion – 00:00:00.0006128
Short Length Data Chain creation – 00:00:00.0000382
Short Length Data Sign – 00:00:00.0351575
Short Length Data Time taken to sign – 00:00:00.1339372
Short Length Data Encryption Started
Short Length Data Time taken to encrypt – 00:00:00.0161288
Short Length Data Time taken to sign and encrypt – 00:00:00.0161288

— Ubuntu 22.04 LTS —

Program Started!!!
Time taken to read the app config – 00:00:00.0000395
Time taken to deserialize app settings – 00:00:00.1430425

Time taken to generate random string – 00:00:00.0004680
Short Length Data Signing Started
Short Length Data Private Key to Object – 00:00:00.1012312
Short Length Data Public Key to Object – 00:00:00.0006185
Chain Info – True
Short Length Data Chain Build – 00:00:00.2273847
Short Length Data Base64 Conversion – 00:00:00.0008246
Short Length Data Chain creation – 00:00:00.0000530
Short Length Data Sign – 00:00:00.0455311
Short Length Data Time taken to sign – 00:00:00.3932579
Short Length Data Encryption Started
Short Length Data Time taken to encrypt – 00:00:00.0196338
Short Length Data Time taken to sign and encrypt – 00:00:00.0196338

Installed same openssl version on both ubuntu newer versions
Cryptography operations should be faster than 20.04 LTS on 22.04 or 24.04 LTS