As far as I can tell, the researchers are describing features of particular Key Pairs that have been generated by Users of the RSA algorithm. The 'garbage-in,

As far as I can tell, the researchers are describing features of particular Key Pairs that have been generated by Users of the RSA algorithm. The 'garbage-in, garbage-out' rule applies. If your RNG sucks, you're going to get weak keys out of it. Is it harder to generate weak Diffie Hellman parameters using a bad RNG? Update: Yes, apparently. From the paper: "Cryptosystems such as RSA that require, during key-setup, multiple secrets are more affected by the apparent difficulty to generate proper random values than systems such as Diffie- Hellman (cf. [8]), ElGamal, and (EC)DSA that require a single secret." That's (mercifully) pretty intuitive.