Duplicated Cryptographics hash functions content in Hash functions chapter.

[pawlos]

I've recently pick-up the book. It looks very informative. Thanks.

I was reading through the chapter about Hash functions and was wondering if there's a duplication of the text about Cryptographic hash function. It's being mentioned on top and then again in the same form later under the Cryptographic hash functions with the same example and code.

I would expect only being introduced on the top and later explain in detail. Is this by choice done like that?