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Re: [openpgp] Memory requirement for Argon2 (draft-06, sec 3.7.1.4)

Justus Winter <justus@sequoia-pgp.org> Thu, 21 July 2022 16:55 UTC

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From: Justus Winter <justus@sequoia-pgp.org>
To: Bruce Walzer <bwalzer@59.ca>, Daniel Huigens <d.huigens@protonmail.com>
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Date: Thu, 21 Jul 2022 18:55:31 +0200
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Subject: Re: [openpgp] Memory requirement for Argon2 (draft-06, sec 3.7.1.4)
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Bruce Walzer <bwalzer@59.ca> writes:

> As a practical example, GnuPG adjusts the amount of computational
> effort so that it takes 0.1 seconds to decrypt on the system the S2K
> operation was done on.

Note that on contemporary systems, it doesn't even take that long to
derive a session key from a password even if you max out the number of
bytes to hash.  In Sequoia, we therefore default to the maximum number
of bytes to hash without doing any kind of measurement.

The S2K mechanism is not suitable anymore for current systems and is in
dire need of replacement.

Best,
Justus

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