Diffie-Hellman operations on retained keys

modulename: compat_dh.ko

and/or

dh.ko

configname: CONFIG_KEY_DH_OPERATIONS

Linux Kernel Configuration
└─>Security options
└─>Diffie-Hellman operations on retained keys
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This option provides support for calculating Diffie-Hellman
public keys and shared secrets using values stored as keys
in the kernel.

If you are unsure as to whether this is required, answer N.

source code: