Cryptographic algorithms are complex mathematical formulas that require powerful microprocessors and good entropy (random data). The more advanced and complex an algorithm is, the more complex calculation will become. Older, slower processors will take substantially longer than newer and faster processors.
Both OpenSSL and mbed TLS are constantly making improvements to both security and performance. While writing this book, I was using my MacBook Pro with the latest version of macOS (10.12.2) and I was going to show performance numbers for the AES cipher set using the openssl speed -evp aes-128-cbc command. The purpose is to show a reproducible performance metric on various platforms.
As you can see in the following screenshot, my Mac has OpenSSL version 0.9.8zh installed. OpenSSL included support for AES-NI with version 1.0, and the performance gains are evident in the first set of table entries (in the Result summary section, given later).
Performance...