Pohlig–Hellman algorithm: Difference between revisions

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\end{matrix}
</math> (using [[Euler's theorem]])</center><br>Note that if <math>g^{\varphi(p)/p_1} \equiv 1 \pmod{p}</math> then the order of ''g'' is less than &phi;(''p'') and <math>e^{\varphi(p)/p_1} \mod p</math> must be 1 for a solution to exist. In this case there will be more than one solution for ''x'' less than &phi;(''p''), but since we are not looking for the whole set, we can require that ''b''<sub>1</sub>=0.<br><br>The same operation is now performed for ''p<sub>2</sub>'' up to ''p<sub>n</sub>''.<br><br>A minor modification is needed where a prime number is repeated. Suppose we are seeing ''p<sub>i</sub>'' for the ''k+1''-th time. Then we already know ''c<sub>i</sub>'' in the equation ''x = a<sub>i</sub> p<sub>i</sub><sup>k+1</sup> + b<sub>i</sub> p<sub>i</sub><sup>k</sup>+c<sub>i</sub>'', and we find ''b<sub>i</sub>'' the same way as before.
:#We end up with enough simultaneous [[congruence|congruences]] so that ''x'' can be solved using the [[Chinese remainder theorem]].
 
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