Hello,

Thank you for a good question. What do you specifically mean with “few ms delay in each mode”?

I understand that this question is about the performance of different security modes of OPC UA. These are None, Sign and Sign&Encrypt. Using signatures or encryption will consume more resources than using no security. It’s application specific if this difference is meaningful for you.

Measuring execution time of a single service call (such as UaClient.readValues call) may be difficult in practice. At least you should measure large amount of executions and take a suitable statistical value. For example, you could try reading same data with different security modes 100 times each and measure average execution time of the UaClient.readValues method call. The average execution time should show that None is the fastest Security Mode and using Sign or Sign&Encrypt adds a small amount of overhead. Also, there should be a notable difference in the performance between signing and also encrypting data meaning that only signing should be faster.