OK...a follow up question (actually, really the same question in a diferent form). Let's say I had a crypto chip or other encryption engine, the code of which I could not see. Now what if someone had monkeyed with it so that (let's say) the pool of prime numbers it drew from was actually a subset of the real pool that should be available for encryption. Let's also say that "somebody" knows this, and can search byte streams for known strings of products of these primes. They can then break this cypherstream very easily. Meanwhile, someone who doesn't know that the code's been tampered with can try to break the cypherstream using traditional brute force methods, and it will appear that this is a truly hard-encrypted message. Now don't get hung up on the details of what I'm saying here...I don't know if this particular example is possible or not. I'm just wondering iF it is possible to tamper with crypto code (particularly as embedded on a chip) so that it appears to all regular users not to have been tampered with, but meanwhile it allows certain privileged users to access encrypted streams fairly easily. AND if this is possible, is there some way to examine the encrypted output and then, say, search for unusual frequency traces of certain sequences, and determine tha the code has been tampered with? Or are there ways to tamper with good cryptocode in ways that can never be detected with actually looking at the originating code?
From: "Tyler Durden" <camera_lumina@hotmail.com> To: camera_lumina@hotmail.com, cypherpunks@lne.com Subject: Intel Security processor + a question Date: Thu, 17 Oct 2002 11:49:33 -0400
Intel is moving Security onto its Network processor chips...a quote also follows.
http://www.lightreading.com/document.asp?site=lightreading&doc_id=22749
(Begin quote) For now, Intel is tackling very high- and low-end systems. The IXP2850 is derived from the IXP2800, which targets 10-Gbit/s line speeds. And back in February, Intel released the IXP425, a network processor with encryption hardware included, targeting low-end boxes such as enterprise routers (see Intel: The Prince of Processors? ).
For both chips, Intel developed its own hardware to handle the DES, triple DES, AES, and SHA-1 encryption standards. In the case of the IXP2850, Intel had left room in the IXP 2800 to add these hardware blocks, because potential customers had shown enough interest in security. We thought about adding crypto [to the IXP2800] as we were building it from the ground up, says Rajneesh Gaur, Intel senior product marketing manager. (End quote)
Got a question for the cognoscenti amongst us... If crypto is performed by hardware, how sure can users/designers be that it is truly secure (since one can't examine the code)? Is there any way to determine whether standard forms of encryption have been monkeyed with in some way (ie, to make those with certain backdoor keys have access at will, and yet still conform to he standard as far users can see)? And, are hardware-based encryption implementations considered suspect from the standard by the more "careful" parts of the crypto community?
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