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To: cs551@merlot.usc.edu
Subject: Re: Question on DELETE 
Date: Sat, 21 Apr 2007 22:15:22 -0700
From: william@bourbon.usc.edu

Someone wrote:

  > No I was asking it the user can use the DELETE command in our
  > assignment to delete a file locally if it didnt do the
  > corresponding STORE but got the file using GET.

It should verify the digital signature and this should fail.
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>



  ----- Original Message -----
  From: william@bourbon.usc.edu
  Date: Saturday, April 21, 2007 8:41 pm
  Subject: Re: Question on DELETE
  To: cs551@merlot.usc.edu
  
  > Someone wrote:
  > 
  >  > Since only the user who created a file using store can delete it
  >  > from the network. So a user who GOT a file cant delete it even
  >  > from his node's permanent storage, right? and its not being asked
  >  > for in this assignment?
  > 
  > If this user has write privilege in HomeDir, he/she can
  > delete the file from the file system by doing "rm" and there
  > is no way to prevent this user from doing this.  Is that what
  > you were asking?
  > 
  > The only way specified in the assignment to delete a file is
  > via the DELETE message and your node should verify digital
  > signature before deleting a file.
  > --
  > Bill Cheng // bill.cheng@usc.edu 
  > <URL:http://merlot.usc.edu/william/usc/>
  > 
  > 
  >  ----- Original Message -----
  >  From: william@bourbon.usc.edu
  >  Date: Friday, April 13, 2007 3:19 pm
  >  Subject: Re: Question on DELETE
  >  To: cs551@merlot.usc.edu
  >  
  >  > Someone wrote:
  >  > 
  >  >  > 	Say two nodes have the same copy of a file (filename, 
  > nonce, and
  >  >  > sha1), and one of them try to 'delete'. It first tries to 
  >  > delete the local
  >  >  > copy, however the signature verification fails. Should it 
  > stop 
  >  > or continue
  >  >  > flooding out Delete to other nodes?
  >  > 
  >  > Yes.  I guess it's possible that the local copy is somehow 
  > corrupted.  > --
  >  > Bill Cheng // bill.cheng@usc.edu 
  >  > <URL:http://merlot.usc.edu/william/usc/>