This was actually the opposite of what I expected.
Since most SMTP servers would still accept spoofed email even when DKIM public key is present among DNS records (it's mostly used to increase spam score), I was expecting the article to focus on closing that gap.
I was pleasantly surprised to read that they want to introduce a signing scheme that, instead, wants to introduce better deniability while keeping cryptographically secure protection against email spoofing.
They achieve that through publishing private keys used for message exchange after a short period, thus making historical emails trivial to forge, and thus introducing easy deniability.
To simplify key management, they introduce a tree-based private key storage, keyed by time range, with an interesting property that parent keys automatically reveal child keys as well, while—crucially—keeping key size limited for transfer purposes!
Since most SMTP servers would still accept spoofed email even when DKIM public key is present among DNS records (it's mostly used to increase spam score), I was expecting the article to focus on closing that gap.
I was pleasantly surprised to read that they want to introduce a signing scheme that, instead, wants to introduce better deniability while keeping cryptographically secure protection against email spoofing.
They achieve that through publishing private keys used for message exchange after a short period, thus making historical emails trivial to forge, and thus introducing easy deniability.
To simplify key management, they introduce a tree-based private key storage, keyed by time range, with an interesting property that parent keys automatically reveal child keys as well, while—crucially—keeping key size limited for transfer purposes!