Tamper-resistant criterion

From the comparing table on the `README.md`, another two libraries (sssa-{golang,ruby}) are secure on the Tamper-resistant. As the notes say, the current library use AEAD to check the integrity of the raw result, so mark as `Tamper-resistant`. The other two libraries, which share the same implementation, do not perform aead, but split the raw input into 256-bit slices and generate polynomial for each slice independently. Why the independent polynomials can pass `Tamper-resistant` review?

Start with the comparing table and notes in README.md, then inspect how the current library and the sssa-golang and sssa-ruby implementations handle integrity and polynomial slices. Done means updating the Tamper-resistant comparison accurately and resolving the question about whether the other implementations meet that criterion.

Written by the indexing model from the issue text.