New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Any recommended parameters for 2015 interactive logins? #19

Closed
gperciva opened this Issue Nov 5, 2015 · 4 comments

Comments

Projects
None yet
3 participants
@gperciva
Member

gperciva commented Nov 5, 2015

"common wisdom" (such as https://godoc.org/golang.org/x/crypto/scrypt) says:

The recommended parameters for interactive logins as of 2009 are N=16384, r=8, p=1.
They should be increased as memory latency and CPU parallelism increases.

Since it's been 6 years, it would be helpful to make a new recommendation (which I'll then put on the website, of course). I mean, non-cryptographers won't have any clue whether they should double N, r, or p, or all of them, or...?

@cperciva

This comment has been minimized.

Show comment
Hide comment
@cperciva

cperciva Nov 5, 2015

Member

In general N should be increased rather than the others... but CPUs haven't really gotten much faster in the past six years. Theoretically it might make sense to increase p to exploit multiple CPU cores, but the scrypt code doesn't use multiple threads yet, so that wouldn't be helpful.

Member

cperciva commented Nov 5, 2015

In general N should be increased rather than the others... but CPUs haven't really gotten much faster in the past six years. Theoretically it might make sense to increase p to exploit multiple CPU cores, but the scrypt code doesn't use multiple threads yet, so that wouldn't be helpful.

@lhunath

This comment has been minimized.

Show comment
Hide comment
@lhunath

lhunath Nov 7, 2015

How was the 2009 recommendation determined?

lhunath commented Nov 7, 2015

How was the 2009 recommendation determined?

@cperciva

This comment has been minimized.

Show comment
Hide comment
@cperciva

cperciva Nov 7, 2015

Member

@lhunath Based on standard rules of thumb which have been used for about four decades: Interactive logins should take no more than 100 ms, while people will wait around 5 seconds to encrypt/decrypt files.

Member

cperciva commented Nov 7, 2015

@lhunath Based on standard rules of thumb which have been used for about four decades: Interactive logins should take no more than 100 ms, while people will wait around 5 seconds to encrypt/decrypt files.

@gperciva

This comment has been minimized.

Show comment
Hide comment
@gperciva

gperciva Feb 23, 2018

Member

I think this is addressed by https://blog.filippo.io/the-scrypt-parameters/ (which we link to on the website and in the README), so I'll close this issue.

Member

gperciva commented Feb 23, 2018

I think this is addressed by https://blog.filippo.io/the-scrypt-parameters/ (which we link to on the website and in the README), so I'll close this issue.

@gperciva gperciva closed this Feb 23, 2018

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment