Questions[hash]

Sorry for the question but let me explain:

I understand that a hash function performs one-way operations on an element without the possibility of RETURNING the operation from the result.

A symmetric encryption function allows bi-directional operations based on a key, but allowing me to encrypt and decrypt.

So far so good but I have a doubt if it is possible to have a kind of fusion between the two and thus have an algorithm that encrypts symmetrically but resulting in a unique "hash". In other words, having something that allows me to encrypt a large amount of information based on a key and resulting in a FIXED LENGTH code just like md5 does.

Is this really possible?

Thank you very much.

I am rephrasing this question from another user, because the original one was unsolvable and the question will possibly be closed, but I think the general technique to solve it might be interesting.

It is essentially about completing the following text, so that the MD5 hash of the complete text is equal to a given one. This is the incomplete text:

with an iron rod) that there are too many redundancies and that only the argument should suffice. What I can say is my name. My name is ......."

We are given the following data:

1. The missing word at the end (which I have represented by .......) has 7 letters, all capital ascii.
2. That word starts with Aand ends with O.
3. The MD5 hash of the final text, encoded in CP-1252, must be7292e0ae2227b2fd1cb089656aeff5e2

What is the missing word?