l Modular Exponentiation 3^8mod11

Enter Modular Exponentiation


      

Solve 38 mod 11 using:

Modular exponentiation

Build an algorithm:

n is our exponent = 8

y = 1 and u ≡ 3 mod 11 = 3

See here

n = 8 is even

Since 8 is even, we keep y = 1

Determine u2 mod p

u2 mod p = 32 mod 11

u2 mod p = 9 mod 11

9 mod 11 = 9
Reset u to this value

Cut n in half and take the integer

8 ÷ 2 = 4

n = 4 is even

Since 4 is even, we keep y = 1

Determine u2 mod p

u2 mod p = 92 mod 11

u2 mod p = 81 mod 11

81 mod 11 = 4
Reset u to this value

Cut n in half and take the integer

4 ÷ 2 = 2

n = 2 is even

Since 2 is even, we keep y = 1

Determine u2 mod p

u2 mod p = 42 mod 11

u2 mod p = 16 mod 11

16 mod 11 = 5
Reset u to this value

Cut n in half and take the integer

2 ÷ 2 = 1

n = 1 is odd

Since 1 is odd, calculate (y)(u) mod p

(y)(u) mod p = (1)(5) mod 11

(y)(u) mod p = 5 mod 11

5 mod 11 = 5
Reset y to this value

Determine u2 mod p

u2 mod p = 52 mod 11

u2 mod p = 25 mod 11

25 mod 11 = 3
Reset u to this value

Cut n in half and take the integer

1 ÷ 2 = 0

Because n = 0, we stop

We have our answer

Final Answer


38 mod 11 ≡ 5