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*To*: Alan Barrett <apb@iafrica.com>*Subject*: Re: Canonical form for signing S-expressions*From*: Derek Atkins <warlord@mit.edu>*Date*: 14 Apr 1997 17:11:32 -0400*Cc*: spki@c2.net*In-Reply-To*: Alan Barrett's message of Mon, 14 Apr 1997 20:41:52 +0000 (UTC)*References*: <Pine.BSF.3.95q.970414203915.1511B-100000@apb-laptoy.apb.alt.za>*Sender*: owner-spki@c2.net

Yep. I hadn't thought about using multiple delimiters, I just wanted to point out the flaw. I'm glad someone else came up with a working alternative. However, I'm wondering if this is too much overhead. Are we adding more bytes in the encoding process than what we're actually encoding? In the long run it probably isn't much overhead, but these examples sure look like it is. I've seen protocols that convert numbers to hex form for transport "to make them readable by a human." Unfortunately this example protocol isn't very extensibile since it limits the size of data that can be input. (This is MIT's Zephyr Protocol, and the conversion is for Kerberos Authenticator information -- it doesn't work with Kerberos v5 because the krb5 authenticators are too big). Mostly, I just want the encoding to be as compact as possible. I'd prefer binary encoding (as opposed to decimal or hex), but that opens up other problems which I doub this group is interested in tackling. -derek Alan Barrett <apb@iafrica.com> writes: > > On 14 Apr 1997, Derek Atkins wrote: > > The only problem with this is that you now have an ambiguous recursion > > problem. How do you know when: > > 30:(1:a,1:b,16:(2:cd,1:e,3:fgh),), > > means > > '((1:a,1:b,16:(2:cd,1:e,3:fgh),)) > > or > > (a b (cd e fgh) > > Oops! Thanks. (I was also missing the "," in "3:fgh,".) > > As Ron Rivest has already pointed out, using different delimiters > can fix that. > > --apb (Alan Barrett) > -- Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory Member, MIT Student Information Processing Board (SIPB) URL: http://web.mit.edu/warlord/ PP-ASEL N1NWH warlord@MIT.EDU PGP key available

**Re: Canonical form for signing S-expressions***From*: Carl Ellison <cme@cybercash.com>

**Re: Canonical form for signing S-expressions***From*: Alan Barrett <apb@iafrica.com>

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