Thank you for showing a useful URL. The answer to your question would be found on the White Paper which the same company, Vandyke, has on their Web: http://www.vandyke.com/solutions/whitepapers.html The latest paper, "Understanding Host Keys" is the one -I think, if I interpreted your question correctly.
The summary of the answer is, "Eve needs the SECRET KEY of Alice in order to impersonate her." Authentication message is encrypted (I am not sure. It might be signed) by the secret key and Bob, who received the authentication message, checks whether the message was really encrypted by Eve's secret key. Therefore simply having Alice's PUBLIC KEY is useless in the MitM attack. Christ, Bryan wrote: > > http://www.vandyke.com/solutions/ssh_overview/ssh_overview_threats.html > > So my question is this... Given the illustration in the URL above, what > prevents Eve from *first* contacting Alice to obtain a fingerprint which > then gets passed to Bob on the first connection attempt? > -- Masahito Gotaishi, Researcher R & D Initiative, Chuo University 1-13-27 Kasuga, Bunkyo, Japan, 112-8551 DDI:03-3817-1621, FAX:03-3817-1606
