[phw]

This idea has since been applied to several other domains. Last year we had a look at all archived RSA keys of Tor relays: https://nymity.ch/anomalous-tor-keys/

We found that several thousand relays that shared prime factors (most part of a research project), ten relays shared moduli, and 122 relays used a non-standard RSA exponent, presumably in an attempt to manipulate the Tor network's distributed hash table, which powers onion services.