Speed improvements and bug fixes in ciphers/rsa_factorization.py

[swenson]

• Using (g ** t) % N is significantly slower than pow(g, t, N) as the values get larger. Replacing this allows even large examples to run nearly instantly.
• Added doctests from the cited sources
• Remove unnecessary extra while/if.
• Added a ValueError if the arguments are invalid. e * d % ((p - 1) * (q - 1)) should be equal to 1, where p and q are primes greater than 2. Hence, (p - 1) * (q - 1) is even, and e * d - 1 will also be even if they are valid.

The underlying algorithm was not changed.

Describe your change:

• [ ] Add an algorithm?
• [x] Fix a bug or typo in an existing algorithm?
• [x] Documentation change?

Checklist:

• [x] I have read CONTRIBUTING.md.
• [x] This pull request is all my own work -- I have not plagiarized.
• [x] I know that pull requests will not be merged if they fail the automated tests.
• [x] This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• [x] All new Python files are placed inside an existing directory.
• [x] All filenames are in all lowercase characters with no spaces or dashes.
• [x] All functions and variable names follow Python naming conventions.
• [x] All function parameters and return values are annotated with Python type hints.
• [x] All functions have doctests that pass the automated testing.
• [x] All new algorithms have a URL in its comments that points to Wikipedia or other similar explanation.
• [x] If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[swenson]

Thanks for the feedback! I believe I have addressed it.

[stale[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[swenson]

I'm going to close this as I realize that the amount of duplication and bad code in this repository means that the maintainers aren't really concerned about quality of entries, performance, usability, or much of anything else, so there's not much of a need for this PR.