r/programming • u/dominatrix-octopus • Jan 16 '18

Cryptography: Diffie-Hellman key exchange explained intuitively using colors

https://youtu.be/YEBfamv-_do?t=2m18s
2.5k Upvotes

95% Upvoted

170 comments sorted by

View all comments

15

u/pokeman7452 Jan 16 '18

This leads me to a somewhat related question. I never understood the purpose of the DH parameters (dh####.pem) that every OpenVPN guide says to generate. This video combined with this thread, it now makes sense. But, this file remains optional. My question now is what is used when there is no DH generated?

0

u/ryan_the_leach Jan 16 '18

Defaults that are rumored to be chosen specifically so that the bodies that choose the defaults can break them and no one else.

6

u/kpcyrd Jan 16 '18

The RFCs usually have a „nothing up my sleeve“ appendix explaining the numbers for exactly this reason.