CERT Advisory CA-2000-09 - Flaw in PGP 5.0 Key Generation. UNIX systems having a /dev/random device running any version of PGP 5.0 are affected. When keys are generated non-interactively and without user-added randomness, on some systems PGP v5.0 generates keys that are not random enough, allowing an attacker to predict keys and therefore recover information encrypted with that key. Additionally, an attacker may be able to forge a digital signature corresponding to a vulnerable key. CERT homepage here.
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