Statistics on the frequency of usage of RSA key public exponents

Question

Are there any publicly available stats regarding how often are specific public exponents used for RSA keys?

Presumably, 65537 is the most commonly used of them, but I'd like to get some notion of which other values one should care about when testing for compatibility.

score 2 · Answer 1 · answered Sep 28 '18 at 14:53

I couldn't find any references to any statistics, however:

All Fermat primes $${3, 5, 17, 257, 65537, 4294967297, 18446744073709551617, … }$$ could be used while regarding the use a proper padding scheme. There is no known weakness for any short or long public exponent for RSA, as long as the public exponent is "correct" (i.e. relatively prime to p-1 for all primes p which divide the modulus).

So why is $ e = 65537$ used most commonly?

Using $e=65537$ (or higher) in RSA is an extra precaution against a variety of attacks that are possible when bad message padding is used. But it's not too large so that it would greatly impact performance speed ($e = 3$ is around 8x faster than $e = 65537$).

So in short: $e = 65537$ is most commonly used as a comprimise, because it's reasonably fast and secure.

Statistics on the frequency of usage of RSA key public exponents

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