[DNSOP] RSA cracking

Jim Reid <jim@rfc1035.com> Thu, 14 January 2010 10:28 UTC

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From: Jim Reid <jim@rfc1035.com>
To: Alfred HÎnes <ah@TR-Sys.de>
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Date: Thu, 14 Jan 2010 10:28:39 +0000
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Cc: namedroppers@ops.ietf.org, IETF DNSOP WG <dnsop@ietf.org>
Subject: [DNSOP] RSA cracking
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On 13 Jan 2010, at 20:58, Alfred HÎnes wrote:

> An international team lead by the BSI (the "German NSA") and others
> has solved the RSA-768 challenge, and experts reportedly expect, due
> to significant progresses, that RSA-1024 will be solved in a rather
> short time, likely by the end of this year or so!

Hmmm. The paper by Klienjung et al (http://eprint.iacr.org/ 
2010/006.pdf) said it took ~2000 Opteron-years and ~2.5 years of  
elapsed time to crack RSA768. So if you change keys every month or  
two, there's not much to worry about.... BTW the authors of that paper  
said they don't expect 1024-bit RSA to be factored for another 5-10  
years with comparable resources to their RSA768 efforts unless  
factoring algorithms improve a lot.

> This means that we should immediately plan operationally for
> widespread use of 2048-bit RSA keys in the "near" future.

True. Some of us deployed 2048-bit RSA keys in 2007. Perhaps your  
friends at BSI might like to crack the KSK or ZSK for rfc1035.se? :-)