I recently came across a video on the net showing the process of key exchange in Diffie Hellmann.
Alice and Bob want to communicate. Eve is the (wo)man in the middle.
This video is the basis of my question http://youtu.be/YEBfamv-_do?t=6m22s
Alice sends the modulo and the prefix to bob. Eve gets that.
What prevents Eve to have a giant table of all the calculations possible given a prefix and a modulo and the public value and intersect thos possibilities with the public value from bob ?
Yes the table would be very big but you can then iterate over the intersecting possibilities and try the numbers on the message up to the point to get something right.
i may miss something, but it is not that hard, even with very big numbers.
So what did I miss ?