It appears that when a prime p is of the form 8k - 1 where 4k - 1 and 8k - 1 are both primes, then the order of each power of 2 mod p is phi(p)/2 where phi() is the Euler's Totient Function.

This is only one part of my conjecture. Here's another part of it:

**Conjecture:**If p is a prime of the form 8k - 1 where 4k - 1 and 8k - 1 are both primes and n is an integer smaller than q such that it is not a power of 2 mod p, then the order of n mod p is phi(p)= p-1

**Example:**Below is an image of the exponentiation tables of Z

_{23}and Z

_{7}.

In my previous entry I called such primes "steady primes". The reason why I chose the name "steady" is because of the "steady", uniform structure of the exponentiation table of Z

_{p}when p is a steady prime.

All elements of Z

_{p}when p is a steady prime have order that is equal to or greater than phi(p)/2. This is also true for the rest of the safe primes, which are the tough primes, but the structure of the exponentiation table of Z

_{p}when p is a tough prime is different. With tough primes every odd power of 2 mod p has order p-1 and every even power of 2 mod p has order phi(p)/2.

**Conjecture:**If p is a steady prime, then phi(p)/2 is also a prime number.

Example: The first few steady primes are: 7,23,47,167,263,359,383,479,503

phi(p)/2 when p is the first few steady primes is equal to: 3,11, 23, 83, 131, 179, 191, 239, 261

Unfortunately, the curious properties of steady primes are not applicable to all products of steady primes. There are some products of steady primes pq with such uniform structure of the exponentiation table of Z

_{pq}but they are kind of rare.

Below is a calculator that can be used to generate powers of powers of integers modulo other integers, the algorithm for which I described here.