On average, 2 RSA keys of 1000 are vulnerable to cracking.

A team of European and American mathematicians analyzed over 11,000,000 certificates belonging to various sites and found that, on average, there are about 2x per thousand of them with weak parameters allowing the recovery of the secret key.


Not only did many of these modules (N) have the same, but for a small part of the public keys, the RSA modules allowed themselves to factorize for the minimum time.

The dock is very voluminous and in English, so those interested are invited to self-reading and exciting .
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Anticipating the questions "how to check?"
The authors apparently wanted to make a public inspection service, but were afraid that this could harm companies if left-handed people checked the vulnerable key. According to their idea, it would not be difficult for knowledgeable people to write such a tool on their own after reading the report.