Calculating Euler phi function

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    Euler Function Phi
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Discussion Overview

The discussion revolves around the computation of the Euler phi function, particularly in the context of large integers and RSA encryption. Participants explore methods for calculating the function and the implications of prime factorization.

Discussion Character

  • Technical explanation, Homework-related, Mathematical reasoning

Main Points Raised

  • One participant inquires about computing the Euler phi function for large integers and mentions a formula for non-prime integers but seeks implementation guidance in Matlab.
  • Another participant notes that computing the Euler phi function typically requires knowledge of the prime factorization of the input, highlighting the difficulty of the factorization problem.
  • A participant clarifies that they are working with RSA encryption and already know two large primes, asking if the Euler phi function for their product N is simply (p-1)(q-1).
  • One participant confirms that the formula for phi(N) is indeed (p-1)(q-1) when N is the product of two primes.

Areas of Agreement / Disagreement

Participants generally agree on the relationship between the Euler phi function and prime factorization, but the discussion includes varying levels of understanding regarding implementation and the factorization problem.

Contextual Notes

The discussion does not resolve the complexities involved in implementing the Euler phi function in programming environments like Matlab, nor does it address the broader implications of the factorization problem in cryptography.

Who May Find This Useful

Readers interested in number theory, cryptography, or computational mathematics may find this discussion relevant.

paton51
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How do i comput the euler phi function of a large interger?
i know that if p is prime then phi(p)=p-1 and I've found a formula for computing non primes but i don't know how to implement in something like Matlab.
Does anyone know how?
 
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AFAIK, computing the Euler phi function requires you to know the prime factorization of the input. Unless you can find it, there's not much you can do.
 
Yes i know the factorisation problem is hard. I am workin with RSA encryption so we know two large primes, the product of which is N this is what i want to do euler phi on.
Since N is the product of two primes (p and q) is phi(N) simply (p-1)(q-1)?
 

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