[Cryptography] The Trouble with Certificate Transparency

[Greg]

Dear Tony,

On Sep 25, 2014, at 2:05 PM, Tony Arcieri <bascule at gmail.com> wrote:

> On Thu, Sep 25, 2014 at 1:52 AM, Ralf Senderek <crypto at senderek.ie> wrote:
> Given the powers of a post-snowden MITM, the claim in Greg's posting seems
> legitimate.
> 
> This same class of attack will work on practically any system

We've already acknowledged on twitter [1] the fact that this class of attack does not work on blockchains and DNSChain.

That is for two reasons:

1. With blockchains, only the owner of a domain can update SSL certificates. With CT and X.509, your domain does not belong to you exclusively, and therefore thousands of others can create SSL certs for your domain.
2. With blockchains, censorship or DoS to the P2P network can only prevent nodes from receiving updates, it does not make them forget what they've already learned. Since most SSL certs are long-lived, the threat is far less significant than it is with CT.

Kind regards,
Greg Slepak

[1] https://twitter.com/taoeffect/status/514884562720399360

--
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