Non-functional protection requirements

Question

The verification code sent to the email as soon as the person signs up for a website is a non-functional requirement of protection or trust?

Answer 1

I would say that it is a Non-functional Safety Requirement because according to Pressman’s definition:

Non-functional requirements are requirements related to the use of the application in terms of performance, usability, reliability, security, availability, maintenance and technologies involved.

PRESSMAN,R.S. Software Engineering 6th Edition, Mcgraw-Hill Publishing, 2006, ISBN: 8586804576