I can't download a library with composer from packagist. This is the error:
[Composer\Repository\RepositorySecurityException]
The contents of https://packagist.org/p/provider-latest%240cbfb40ab72a881d21b70f78286d39cd72e3b0eb8704c13e79dc49624
e549973.json do not match its signature. This could indicate a man-in-the-middle attack. Try running composer again
and report this if you think it is a mistake.
And the site of packagist is unvalaible.