Per-Entity Metadata Working Group

["Cantor, Scott" <>]

> Just for the background information, another concern was the server
> security which is assumed in TLS.  I'm not suggesting md.incommon.org is
> not secure but it was difficult to quantify and it was certainly less
> secure than the signing operation.  Ops also wanted to reserve the
> flexibility of hosting its stand-by servers in co-locations without
> special requirements on its physical security.

Right, that's the fundamental difference.

Signing Pro:
- self-contained / portable security model
Con:
- subject to MITM threats

Transport Pro:
- end to end security
Con:
- highly dependent on physical deployment characteristics that are difficult 
to replicate widely

I wouldn't necessarily argue that both don't have their place, but we 
implement both and long experience has led us to believe that it's better to 
attack the MITM problem with signing somehow than give up the flexibility.

I think probably the best option is to sign, use TLS, but not go overboard 
trying to lock down the TLS part. That provides reasonable protection against 
low-cost active attacks without relying on it exclusively.

-- Scott