Understanding Cryptography by Christof Paar and Jan Pelzl - Chapter 1 Solutions - Ex1.6

- 1 min

Exercise 1.6

Compute without a calculator:

1. 1/5 mod 13
2. 1/5 mod 7
3. 3 · 2/5 mod 7

Solution

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In order to perform a division by $x$, we must find the multiplicative inverse $x^{-1}$ and multiply by it.

1.

2.

3.