Schnorr sigs vs pairing sigs

Schnorr sigs vs pairing sigs
2020-03-06  6:40 ` Lloyd Fournier
  
From: Erik Aronesty @ 2020-03-05 19:01 UTC (permalink / raw)
  To: Bitcoin Protocol Discussion

Schnorr sigs rely so heavily on the masking provided by a random
nonce.   There are so many easy ways to introduce bias (hash + modulo,
for example).

Even 2 bits of bias can result in serious attacks:

https://ecc2017.cs.ru.nl/slides/ecc2017-tibouchi.pdf

Maybe pairing based sigs  - which are slower - might be both more
flexible, and better suited to secure implemetnations?


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2020-03-05 19:01 [bitcoin-dev] Schnorr sigs vs pairing sigs Erik Aronesty

  
From: Lloyd Fournier @ 2020-03-06  6:40 UTC (permalink / raw)
  To: Erik Aronesty, Bitcoin Protocol Discussion

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Hi Erik,

There are a strong arguments for and against pairing based sigs in Bitcoin.
One very strong argument in favour over non-deterministic signatures like
Schnorr over BLS is it enables a kind of signature encryption called
"adaptor signatures". This construction is key to many exciting up and
coming layer 2 protocols and isn't possible unless the signature scheme
uses randomness.

self plug: I have a paper on this topic called "One-Time Verifiably
Encrypted Signatures A.K.A Adaptor Signatures"
 https://github.com/LLFourn/one-time-VES/blob/master/main.pdf

LL


On Fri, Mar 6, 2020 at 6:03 AM Erik Aronesty via bitcoin-dev <
bitcoin-dev@lists•linuxfoundation.org> wrote:

> Schnorr sigs rely so heavily on the masking provided by a random
> nonce.   There are so many easy ways to introduce bias (hash + modulo,
> for example).
>
> Even 2 bits of bias can result in serious attacks:
>
> https://ecc2017.cs.ru.nl/slides/ecc2017-tibouchi.pdf
>
> Maybe pairing based sigs  - which are slower - might be both more
> flexible, and better suited to secure implemetnations?
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists•linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>

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