I believe the minimum considered secure for standard DHE is 2048 bits. Qualys will label 1024 bit DHE exchanges as WEAK. 256-bit+ ECDHE is also considered sec

I believe the minimum considered secure for standard DHE is 2048 bits. Qualys will label 1024 bit DHE exchanges as WEAK. 256-bit+ ECDHE is also considered secure on the standard curves (x25519, secp256r1, secp384r1).