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From: randy@ms.uky.edu (Randy Appleton)
Newsgroups: comp.os.research
Subject: Amoeba
Message-ID: <14127@darkstar.ucsc.edu>
Date: 4 Apr 91 06:19:01 GMT
Sender: usenet@darkstar.ucsc.edu
Organization: University Of Kentucky, Dept. of Math Sciences
Lines: 22
Approved: comp-os-research@jupiter.ucsc.edu

I hope this is the appropiate place to ask questions about the Amoeba
operating system.  Is some other newsgroup better?

In Amoeba, when a process creates what in UNIX would be a socket,
it provides what is called 'g'.  The socket that is created is f(g),
where f() is a one-way function. This provides a sense of security, since
it is then possible to advertise well-known port numbers f(g) and still
know that only you can create that port, since only you know 'g'.

But isn't it true that anyone who has your source can just read it to find
'g'.  In perticular, if the file server is advertised as findable at
port f(g), cannot anyone who has the source just scan it for 'g', and then
put up a fake server?

In UNIX this is not a problem, since the lowest 1024 ports are reserved 
for the superuser, and all the useful advertised ports are in that range.

Finally, in Amoeba if someone has allready created a port at 'x', what 
happens if I try to create a new one?

-Thanks
-Randy