Re: scrypt ASICs - litecoin N, r, p settings - Re: Revisiting the SHA1 default password hash

["Lorenzo M. Catucci" <lorenzo@sancho.ccd.uniroma2.it>]

On 07/03/2017 19:13, Emily Backes wrote:
>> Requiring 1GB for a password hash will preclude using it on small devices, 
>> e.g. raspberry pi.
>>
>> Even 16MB is excessive.
> 
> It's sounding like the newer and more complicated hashes have a lot of configurable features that may need site-local tuning.  Should these be part of e.g. slapd.conf config or be settings embedded in the value format for later clarity, like
> 
> {HASHNAME:attr=val,attr=val,attr=val}SnVzdCBhbiBleGFtcGxlLCBzaWxseQ==
> 
> Considering the size of some of these newfangled hashes, attribute length doesn't look to be a relevant concern any longer.  Realistically this would probably be a better way to express things like salt values in addition to the iteration counts and so on.  If a structured value is what we really want there, BER might be more appropriate, possibly with a leading {EXTENDED-STRUCTURE} hash declaration.
> 
> --
> Emily Backes
> Symas Corporation
> ebackes@symas.com
> 

I'd humbly suggest avoiding custom encodings and sticking with the already
defined modular crypt format encodings, and available at:

https://gitlab.com/jas/scrypt-unix-crypt/blob/master/unix-scrypt.txt
https://github.com/P-H-C/phc-winner-argon2/blob/master/src/encoding.c

prefixed by a (reduntant) hash identifier, like '{scrypt}' or '{argon}' to
avoid "strange" interactions with the host's libc defined crypt(3).

Thank you,

	lorenzo