Re: [Cfrg] IBE checking...

"Paterson, Kenny" <> Mon, 21 March 2016 17:09 UTC

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From: "Paterson, Kenny" <>
To: Tanja Lange <>, Stephen Farrell <>
Thread-Topic: [Cfrg] IBE checking...
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Subject: Re: [Cfrg] IBE checking...
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From the specification, it's pretty clear that this proposal does not use

>In common
>with other identity-based encryption/signature approaches, it is
>based on the use of elliptic curves.  Unlike some, it does not use
>"pairings" (bilinear maps from a product of two elliptic curve groups
>to another group).

So the recent analysis in eprint 2015/1027 is not relevant here.



On 21/03/2016 15:09, "Cfrg on behalf of Tanja Lange"
< on behalf of> wrote:

>Dear Stephen, dear all,
>> While I'm not a fan of IBE myself, and there's still no published
>> analyses, I don't think we can block experimental stuff for those
>> reasons alone. (Otherwise CFRG might have a hard time producing
>> some new experimental specs for example.) Mind you, that does
>> assume that the rest of the world know the difference between
>> experimental and standards-track RFCs, which is not actually
>> true, but we do also need to stick with the rules of the game
>> that we've setup so I think this is the correct, if not the
>> optimal, outcome.
>There is ongoing work on breaking the discrete log problem in the
>target group (the group where the pairing maps to). The most
>recent publication I'm aware of is
>At ECC 2015 Aurore Guillevic gave a talk
>Computing individual discrete logarithms faster in F_{p^n} with the
>Number Field Sieve algorithm
>in which she is targeting fields with 1<=n<=12, which are exactly the
>fields appearing as targets of pairings. For abstract and slides see
>So, at this moment I'd suggest some caution for parameter suggestions.
>All the best
>	Tanja
>Cfrg mailing list