Could I repost those questions on math.se for example? I would wait some time to do that, since only a week have passed since the first question. In addition, should I delete those questions in crypto.se in the case I can repost those in another forum?
Cross posting the same question to multiple stackexchange sites is frowned upon. If you do move your question to a new site, please ensure that you delete the one on our site (or, ask a moderator to migrate your question for you).
How to attract interest from the users so your question gets responded/commented/viewed?
It happened me in other forums, and makes me feel frustrated, feels like I'm going in the wrong direction.
The first part is to realize that stackexchange is not a forum. It is a question and answer site.
The difference is that forums are designed for discussion, and stackexchange is not.
Every user on a forum can post their thoughts on the subject, and it's common to have back-and-forth conversations.
On stackexchange, a "question" that requires everyone to post their thoughts on the subject and have back-and-forth discussion is the antithesis of what the site is for. Think of the topics on crypto.stackexchange as entries in a Handy Cryptography Answer book. Each question should have a concise and objective answer.
About your questions
Question number 2 is involved. It will require the reader to make a conscious effort to sit down and read and understand the context. Asking too much of the reader will tend to lead to fewer readers.
But a bigger issue is that there is no concrete "question" as such. The bottom line says:
What are other limitations and advantages of using the self power map of distinct generators for solving DLP in $Z^∗_p$.
This is an open-ended discussion type of question - It could require a plethora of authors to write an entire book to discuss the limitations and advantages of X or Y. These kinds of question are not a great fit for our site. A question that can be objectively and definitively answered as opposed to discussed has a much better chance of both remaining open and being answered.
I don't believe that simply migrating this question to a different stackexchange site will fix these problems.
Question 1 is about multivariate cryptography. From what I can tell, there are not very many users that work with this subject. There are a grand total of 2 questions on our site tagged with
I think that the issue here is simply a lack of expertise. The intersection of users that have the know-how to answer this question with the users that have the time and inclination to do so is possibly an empty set.
It's possible that users of a math stackexchange will have enough familiarity with multivariate polynomials to be able to answer the question from that perspective. It might require the question to be re-phrased. I don't use the math stackexchange sites, so I don't know for certain.