Re: [Cfrg] Round 2 of the PAKE selection process

"Hao, Feng" <> Wed, 20 November 2019 10:29 UTC

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From: "Hao, Feng" <>
To: "Stanislav V. Smyshlyaev" <>, CFRG <>
CC: "" <>
Thread-Topic: [Cfrg] Round 2 of the PAKE selection process
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Date: Wed, 20 Nov 2019 10:29:16 +0000
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Subject: Re: [Cfrg] Round 2 of the PAKE selection process
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Dear Stanislav (and the review panel),

Many thanks for the update.

For the benefits of openness and transparency, can you give reasons why these four were selected and the rest were removed? I couldn’t find those on your slides.

I’m sure that’ll be helpful for people on the CRFG to understand better this selection process.


From: Cfrg <> on behalf of "Stanislav V. Smyshlyaev" <>
Date: Wednesday, 20 November 2019 at 06:02
To: "" <>
Cc: "" <>
Subject: [Cfrg] Round 2 of the PAKE selection process

Dear CFRG,

As we've announced at the CFRG session today, now we're starting the Round 2 of the PAKE selection process.

We have narrowed down choices to: two balanced (SPAKE2 and CPace) and two augmented (OPAQUE and AuCPace).

Some additional information can be found in my slides from the IETF 106 CFRG meeting:

Please take a look at the plan and especially at Stage 1 - please send your additional questions to be considered at Round 2 to<> until December, 5th.

Round 2 of the PAKE selection process
Stage 1: November, 21st - December, 5th
Additional questions for all four candidates are collected from CFRG participants  (and Crypto Review Panel members). The questions can be of one of possible types:
a) Requests for clarifications for the candidate protocols or their proposed modifications (e.g., security of CPace and AuCPace without negotiation of sid, security and convenient of SPAKE2 with a hash2curve function used to obtain M and N for each pair of identifiers).
b) Questions to be taken into account in addition to ones collected at Stage 1 of Round 1 (e.g., quantum annoyance, post-quantum preparedness).
The questions should be sent to<>.

Stage 2: December, 10th - December, 17th
A list of new questions is published on; the CFRG is asked whether anything else should be added.

Stage 3: December 25th - February, 10th
The authors of the candidates prepare their replies to the additional questions/requested clarifications.

Stage 4: February, 12th - March, 10th
Crypto Review Panel members prepare new overall reviews (for all 4 remaining PAKEs) taking into account both the reviews obtained on Round 1 and new information obtained during Round 2.

IETF 107:
The CFRG chairs discuss the obtained reviews and make their recommendations to CFRG (or convey to CFRG that they can’t make a recommendation yet).
If everything is clear:
- one (or zero) balanced PAKE is selected;
- one (or zero) augmented PAKE is selected;
- the process with CFRG document “Recommendations for password-based authenticated key establishment in IETF protocols” is initiated: all practically important recommendations (parameter selection, protecting implementations against side-channel attacks, handling of counters etc.) must be given there.

Best regards,
Stanislav Smyshlyaev
CFRG Secretary