Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-17 Thread Paul Crowley
At a stretch, one can imagine circumstances in which trying multiple seeds to choose a curve would lead to an attack that we would not easily replicate. I don't suggest that this is really what happened; I'm just trying to work out whether it's possible. Suppose you can easily break an elliptic

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-13 Thread John Kelsey
On Sep 10, 2013, at 3:56 PM, Bill Stewart bill.stew...@pobox.com wrote: One point which has been mentioned, but perhaps not emphasised enough - if NSA have a secret backdoor into the main NIST ECC curves, then even if the fact of the backdoor was exposed - the method is pretty well known -

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-11 Thread Viktor Dukhovni
On Tue, Sep 10, 2013 at 12:56:16PM -0700, Bill Stewart wrote: I thought the normal operating mode for PFS is that there's an initial session key exchange (typically RSA) and authentication, which is used to set up an encrypted session, and within that session there's a DH or ECDH key exchange

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-11 Thread Bill Stewart
At 10:39 AM 9/11/2013, Phillip Hallam-Baker wrote: Perfect Forward Secrecy is not perfect. In fact it is no better than regular public key. The only difference is that if the public key system is cracked then with PFS the attacker has to break every single key exchange and not just the keys in

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-11 Thread Phillip Hallam-Baker
On Wed, Sep 11, 2013 at 2:40 PM, Bill Stewart bill.stew...@pobox.comwrote: At 10:39 AM 9/11/2013, Phillip Hallam-Baker wrote: Perfect Forward Secrecy is not perfect. In fact it is no better than regular public key. The only difference is that if the public key system is cracked then with PFS

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-11 Thread Phillip Hallam-Baker
On Tue, Sep 10, 2013 at 3:56 PM, Bill Stewart bill.stew...@pobox.comwrote: At 11:33 AM 9/6/2013, Peter Fairbrother wrote: However, while the case for forward secrecy is easy to make, implementing it may be a little dangerous - if NSA have broken ECDH then using it only gives them plaintext

[Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread Perry E. Metzger
One solution, preventing passive attacks, is for major browsers and websites to switch to using PFS ciphersuites (i.e. those based on ephemeral Diffie-Hellmann key exchange). It occurred to me yesterday that this seems like something all major service providers should be doing. I'm sure

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread Peter Saint-Andre
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 9/6/13 8:36 AM, Perry E. Metzger wrote: One solution, preventing passive attacks, is for major browsers and websites to switch to using PFS ciphersuites (i.e. those based on ephemeral Diffie-Hellmann key exchange). It occurred to me yesterday

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread Raphaël Jacquot
On 06.09.2013 18:20, Peter Saint-Andre wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 9/6/13 8:36 AM, Perry E. Metzger wrote: One solution, preventing passive attacks, is for major browsers and websites to switch to using PFS ciphersuites (i.e. those based on ephemeral Diffie-Hellmann

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread Daniel Veditz
On 9/6/2013 9:52 AM, Raphaël Jacquot wrote: To meet today’s PCI DSS crypto standards DHE is not required. PCI is about credit card fraud. Mastercard/Visa aren't worried that criminals are storing all your internet purchase transactions with the hope they can crack it later; if the FBI/NSA want

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread Peter Fairbrother
On 06/09/13 15:36, Perry E. Metzger wrote: One solution, preventing passive attacks, is for major browsers and websites to switch to using PFS ciphersuites (i.e. those based on ephemeral Diffie-Hellmann key exchange). It occurred to me yesterday that this seems like something all major service

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread ianG
On 6/09/13 20:15 PM, Daniel Veditz wrote: On 9/6/2013 9:52 AM, Raphaël Jacquot wrote: To meet today’s PCI DSS crypto standards DHE is not required. PCI is about credit card fraud. So was SSL ;-) Sorry, couldn't resist... Mastercard/Visa aren't worried that criminals are storing all

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread Ben Laurie
On 6 September 2013 17:20, Peter Saint-Andre stpe...@stpeter.im wrote: Is there a handy list of PFS-friendly ciphersuites that I can communicate to XMPP developers and admins so they can start upgrading their software and deployments? Anything with EDH, DHE or ECDHE in the name...

Re: [Cryptography] People should turn on PFS in TLS (was Re: Fwd: NYTimes.com: N.S.A. Foils Much Internet Encryption)

2013-09-06 Thread Anne Lynn Wheeler
we were brought in as consultants to a small client/server startup that wanted to do payment transactions on their server, they had this technology they called SSL they wanted to use, the result is now frequently called electronic commerce. The two people at the startup responsible for the