Assurance

["Joe St Sauver" <>]

Hi!

"Capehart,Jeffrey D" 
<>
 commented:

#The SSL Labs website does a fantastic job of documenting server encryption! 
#
#Unfortunately, my tests gave a "C" grade to our servers, so it looks like 
#there is room for improvement. 

Many times it's just a matter of tweaking the configuration of the server --
ten minutes is sometimes all it takes to go from a "C" (or worse) to an "A"

And FWIW, I think it's really worth taking the time to get the good marks on
this one. :-)

#For Higher Ed, would it be reasonable to use exception (footnote) #22 and 
allow
#RC4 Encryption in SSL/TLS and still claim NIST compliance? 
#
#NIST TLS-SSL SP800-52:
#
# TLS_RSA_WITH_RC4_128_SHA   (#22)
#
#(#22) RC4 is not a FIPS-approved cryptographic algorithm. For this reason, 
#cipher suites with RC4 should be offered only when communicating with 
#non-government entities in limited, low risk situations for the transfer 
#of non-Federal data when a FIPS-approved encryption algorithm is not 
#supported. Normally this cipher suite should not be offered.

While I don't claim any expertise in crypto, I am familiar with some of the 
attacks against RC4, and my recommendation would be to avoid using it. 

I know, I know, it was the one cipher that wasn't hit by the BEAST attacks, 
so a lot of people began using it, and you'll also see it used by some of 
the most heavily traficked sites out there (including Google) because it is 
quite CPU efficient, but I would still urge you to avoid using it, even if
FIPS allowed it, because it just keeps on biting people.

For example, back in 2001, some ssh users got bit by RC4, see
"Passwords sent via SSH encrypted with RC4 can be easily cracked,"
http://www.kb.cert.org/vuls/id/565052

Microsoft used RFC4 for Word and Excel, badly. See for example "Microsoft
RC4 Flaw," http://www.schneier.com/blog/archives/2005/01/microsoft_rc4_f.html

RC4 also underlies WEP, the badly flawed wireless encryption protocol that
no one should ever use. 

On the other hand, in fairness, if you want support for the proposition
that RC4 is just peachy keen for SSL/TLS, check out:

"Is RC4 safe for use in SSL?"
http://blog.ivanristic.com/2009/08/is-rc4-safe-for-use-in-ssl.html

Regards,

Joe