There is an explanation of math behind the RSA on: What is the relation between RSA & Fermat's little theorem? It is answered by Antony Vennard. It looks very interesting, but unfortunately Antony is not defining many of the terms. I would like to have a place where I can ask additional questions regarding Antony's answer and get clarification from either him, or anyone else who knows the subject.

I wrote my question in the answer field, and it was deleted. But I could not find a field or asking related questions.

I don't want to ask a new question, because my question is about the existing answer. For example I'd like to know how the definition of ϕ(p,q). He is only defining ϕ(p), but not ϕ of a set of a pair of numbers. This is just one example.

Ideally I'd like to see the explanation with examples of concrete numbers used, and how it relates to cryptography.

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## migrated from crypto.stackexchange.comApr 12 '13 at 11:09

This question came from our site for software developers, mathematicians and others interested in cryptography.

Welcome to Crypto.StackExchange, Veet! I'm afraid posting a new question is not the way to do it; if you don't delete this question yourself, it will likely be deleted soon. Questions here need to be self-contained. Once you gain a bit more reputation, you can post a comment below Antony's answer. Or, if you can formulate a self-contained question that is of interest in its own right, you can post a separate question. Make sure to read the FAQ first. In this case, any good textbook that describes RSA will answer your question about the definition of $\phi(pq)$. –  D.W. Apr 12 '13 at 4:53
I'm pretty sure that it's a typo for ϕ(pq) (ϕ applied to the product). That's what the definition calls for. –  Gilles Apr 12 '13 at 12:32