Using Diffie-Hellman Cryptography

You can control the minimum size in bits of the modulus length of the Diffie-Hellman (DH) group that is used to negotiate with connecting peers when using DH cipher suites.

You can specify modulus sizes of 512, 1024, 2048 and 4096 bits.

The default modulus group size is 2048 bits. If you need to work with peers that only support a smaller key size, or you wish to set support to 4096 bits, then you can specify a new value for the DH minimum group size field in either a listener's SSL options (I601) or the MF Directory Server tab.

Note: If you specify a minimum group size that does not match one of the permitted values listed above, then the value is rounded to the next highest in the list. For example, 1034 is rounded up to 2048 bits.