The gmail DKIM signatures are not a reliable verification that the contents of an email have not been modified. The algorithm and key length of the signatures used by gmail (sufficient for anti-spam) are cracked with an honestly trivial amount of hardware according to RSA in 2003 [1]. Since the premise here is that a state-backed adversary is involved, we can reasonably expect that the keys are compromised.

[1] https://www.emc.com/emc-plus/rsa-labs/historical/twirl-and-r...

Gmail DKIM uses rsa-2048 keys (their key has a selector named "20120113" suggesting this key was in use since 2012, but I didn't do DNS historical digging to confirm). 2048 bit is still believed to be secure enough, even against a state actor, and even the article you linked says it. Either way 2048 bit does not just require a "trivial amount of hardware" (even from a state actors perspective)

The keys in at least several of the Wikileaks emails are 1024-bit. Those are specifically what I was referring to.

Others are signed by hillaryclinton.com, which was likely compromised as well.

The leaked Podesta content goes back quite some time, so yes, there are old emails in there that still had DKIM signatures from a 1024 key.

The email in question is not one of those, and uses the 2048 bit key (emailid/2038).

Also, your assertion that hillaryclinton.com was compromised ... where did you get that? Those emails were released by the govt because of FOIA requests. The DNC was hacked and therefore "compromised" by persons unknown (but some people did a lousy job of attributing it to Russia). The DNC is not hillaryclinton.com, tho.

Yeah, you're correct a lot of the emails use 2048-bit RSA for the DKIM signature. I trust those more than the 1024-bit signatures. I have a pretty heavy distrust of all of this, because from the sidelines I can't tell who is manipulating what. I don't blindly trust the cryptography because I don't know the capabilities of the adversary or what side channel attacks were present. That probably sounds stupid, but I'm feeling a whole lot of distrust of everyone involved.

Following that, my assertion that hillaryclinton.com was compromised was completely evidence-free. That's a personal assumption due to the significant lack of security expertise by the maintainer of the server. There are plenty of emails sent between clintonemail.com and the DNC gmail accounts that CC Podesta and were included in the Wikileaks dumps.

The DNC was hacked by two Russian actors according to CrowdStrike. I trust CrowdStrike in this assessment.

https://www.crowdstrike.com/blog/bears-midst-intrusion-democ...