Re: Ed25519 Signature 2018

On 05/07/2018 02:22 PM, Mike Lodder wrote:
> So let me state that I'm still in favor of using SHA2. Keccak is an 
> awesome algorithm for SHA3 but NIST hardened it too much that it is 
> slower than SHA2. The reasons many are staying away from SHA3 are speed 
> and security. SHA2 is still considered secure so there hasn't been a 
> need for a replacement yet. Many crypto people like BLAKE2b because it 
> has similar characteristics to SHA2 but has been shown to be faster 
> without sacrificing security. The same could be done with Keccak given 
> the right settings. So for now I would vote to just use the 
> Ed25519Signature2018 with SHA2. If SHA2 is broken in the future, a newer 
> version could be made. I don't agree that we've done something wrong if 
> the version changes in the same year. You could everything correctly but 
> a security issue arrises that makes the current spec weak or broken in 
> the same year you write it. Hopefully that doesn't happen but could.
> 
> For future reference what versioning should be used then if such a 
> change is needed.

In the event that this happens, the specific change (for example, SHA2
vs. SHA3) required should be captured in the cryptosuite name.

Keep in mind that capturing the year in the cryptosuite name is done as
a signal to users that they should consider upgrading if the year they
are using it in does not match the current year (or the delta is
significant).

This doesn't mean that there is "one suite to rule them all" for a given
year. Though, it is preferable to keep the number of suites per year
minimal for both security and interoperability purposes. Too much
agility is a bad thing.


> 
> Do you know of an IETF RFC that spec's Ed25519
> signatures using FIPS 202?
> Not right now.
> 
> On Mon, May 7, 2018 at 11:57 AM, Manu Sporny <msporny@digitalbazaar.com 
> <mailto:msporny@digitalbazaar.com>> wrote:
> 
>     On 05/07/2018 01:53 PM, Vaneev Bogdan wrote:
>     > Where can I find a sources for this spec? It seems this repo
>     > contains rendered page.
> 
>     Every spec should have a Github link at the top under "Source control".
>     Here's the one for the spec you were looking at:
> 
>     https://github.com/w3c-dvcg/lds-ed25519-2018/
>     <https://github.com/w3c-dvcg/lds-ed25519-2018/>
> 
>     -- manu
> 
>     -- 
>     Manu Sporny (skype: msporny, twitter: manusporny, G+: +Manu Sporny)
>     Founder/CEO - Digital Bazaar, Inc.
>     blog: Veres One Decentralized Identifier Blockchain Launches
>     https://tinyurl.com/veres-one-launches
>     <https://tinyurl.com/veres-one-launches>
> 
> 
> 
> 
> -- 
> Mike Lodder
> Senior Crypto Engineer
> 
> 


-- 
Dave Longley
CTO
Digital Bazaar, Inc.
http://digitalbazaar.com

Received on Monday, 7 May 2018 18:42:46 UTC