Egypt is one of the safest countries in the Middle East for visitors, and South Sinai is considered especially safe. In practice, the biggest risks tourists usually face are chaotic traffic in big cities, occasional stomach upsets, dehydration, and too much sun.
South Sinai is not only protected by the Egyptian authorities but also watched over by the local Bedouin tribes, who are known for their hospitality and strong presence across the region. Nobody can pass through the rugged mountainous interior without being noticed by the Bedouin.
Around a decade ago there were security issues in a small pocket of North Sinai near the Gaza border. These problems were contained, and the affected area is far from the tourist destinations of South Sinai anyhow.
The map below was published in 2015, around the time when the situation was stabilizing.

To ensure safety and security, there are checkpoints on the roads throughout South Sinai, and visitors travelling into remote desert or mountain areas need to register with local authorities. These procedures may feel unusual to some visitors, but they are intended for your protection.
As with travel anywhere in the world, visitors should use common sense, stay informed, and respect local customs and advice.
THE SINAI: The Sinai Peninsula > The Bedouin > Transport > Safety & Security