Re: [TLS] TLS and hardware security modules - some issues related to PKCS11

Bill Frantz <> Wed, 18 September 2013 00:21 UTC

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Date: Tue, 17 Sep 2013 17:21:05 -0700
From: Bill Frantz <>
To: Michael StJohns <>
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Subject: Re: [TLS] TLS and hardware security modules - some issues related to PKCS11
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On 9/17/13 at 8:45 AM, (Michael StJohns) wrote:

>Um.  No, not if you designed things properly.  It should be 
>possible for any protocol the IETF designs to do all the crypto 
>operation inside a hardware module and not depend on the weak 
>security of a general purpose computer.

While I have no objections to this requirement, I'm not sure 
that hardware is more secure than software if your attacker is a 
large country national crypto agency or sophisticated criminal 
gangs. I worry about Russia, England, China, France etc. as well 
as the USA.

Without taking the chips apart, even validated hardware can be 
replaced at the chip foundry with a different implementation 
which leaks keys via paths such as IVs or uses bogus random numbers.

These attacks can be minimized by using forward security -- more 
keys to attack/leak; making IVs deterministic based on the plain 
text and checked; using a cypher in counter mode for IVs, 
calculating them separately at each end, and not transmitting 
them etc.

There is no real safe heaven these days.

Cheers - Bill

Bill Frantz        | Truth and love must prevail  | Periwinkle
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