Re: [Cryptography] Why prefer symmetric crypto over public key crypto?

2013-09-08 Thread Jaap-Henk Hoepman
Symetric cryptography does a much easier thing. It combines data and some mysterious data (key) in a way that you cannot extract data without the mysterious data from the result. It's like a + b = c. Given c you need b to find a. The tricks that are involved are mostly about sufficiently

Re: [Cryptography] Why prefer symmetric crypto over public key crypto?

2013-09-07 Thread Jaap-Henk Hoepman
Public-key cryptography is less well-understood than symmetric-key cryptography. It is also tetchier than symmetric-key crypto, and if you pay attention to us talking about issues with nonces, counters, IVs, chaining modes, and all that, you see that saying that it's tetchier than that is

Re: [Cryptography] Why prefer symmetric crypto over public key crypto?

2013-09-07 Thread Jaap-Henk Hoepman
I have also, in debate with Jerry, opined that public-key cryptography is a powerful thing that can't be replaced with symmetric-key cryptography. That's something that I firmly believe. At its most fundamental, public-key crypto allows one to encrypt something to someone whom one does not

[Cryptography] Why prefer symmetric crypto over public key crypto?

2013-09-06 Thread Jaap-Henk Hoepman
(and thus subverted) CA to get the recipients public key. What other reasons could there be for this advice? Best, Jaap-Henk (I apologise for typos and being terse; this mail was written on an iPad) -- Jaap-Henk Hoepman TNO, Groningen Dept. of Computer Science Radboud University Nijmegen (m) j

Re: serious threat models

2006-02-03 Thread Jaap-Henk Hoepman
.wcelltap0202/BNStory/International/ --Steven M. Bellovin, http://www.cs.columbia.edu/~smb - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED] -- Jaap-Henk Hoepman

Re: Face and fingerprints swiped in Dutch biometric passport crack (anothercard skim vulnerability)

2006-02-03 Thread Jaap-Henk Hoepman
.. | | | - | The Cryptography Mailing List | Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED] - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED] -- Jaap-Henk Hoepman

Re: Unforgeable dialog.

2006-02-03 Thread Jaap-Henk Hoepman
unsubscribe cryptography to [EMAIL PROTECTED] -- Jaap-Henk Hoepman | I've got sunshine in my pockets Dept. of Computer Science | Brought it back to spray the day Radboud University Nijmegen |Gry Rocket (w) www.cs.ru.nl/~jhh | (m) [EMAIL PROTECTED] (t) +31 24 36 52710

Re: Is there any future for smartcards?

2005-09-12 Thread Jaap-Henk Hoepman
PROTECTED] writes: Is there a real problem that they uniquely solve, sufficient to drive the building of the needed infrastructure? I don't see it, and I'd love to be made smarter. -- Pat Farrell http://www.pfarrell.com -- Jaap-Henk Hoepman | I've got sunshine in my pockets Dept

Re: the limits of crypto and authentication

2005-07-19 Thread Jaap-Henk Hoepman
cryptography to [EMAIL PROTECTED] -- Jaap-Henk Hoepman | I've got sunshine in my pockets Dept. of Computer Science | Brought it back to spray the day Radboud University Nijmegen |Gry Rocket (w) www.cs.ru.nl/~jhh | (m) [EMAIL PROTECTED] (t) +31 24 36 52710/53132 | (f) +31 24

Re: the limits of crypto and authentication

2005-07-19 Thread Jaap-Henk Hoepman
.) - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED] -- Jaap-Henk Hoepman | I've got sunshine in my pockets Dept. of Computer Science | Brought it back to spray the day Radboud University Nijmegen

Re: quantum hype

2003-09-22 Thread Jaap-Henk Hoepman
a 2048 bit number. -- Jaap-Henk Hoepman | I've got sunshine in my pockets Dept. of Computer Science | Brought it back to spray the day University of Nijmegen |Gry Rocket (w) www.cs.kun.nl/~jhh | (m) [EMAIL PROTECTED] (t) +31 24 36 52710/531532 | (f) +31 24

Security of DH key exchange

2003-06-20 Thread Jaap-Henk Hoepman
of the adversary of distinguishing h(g^{ab}) from k is negligible in _n_). References to this are much appreciated. Regards, Jaap-Henk -- Jaap-Henk Hoepman | I've got sunshine in my pockets Dept. of Computer Science | Brought it back to spray the day University of Nijmegen |Gry

Re: Maybe It's Snake Oil All the Way Down

2003-06-08 Thread Jaap-Henk Hoepman
? Make the cellphone companies build good crypto into their systems? Any ideas how to do that? Nope. Cellphone companies are big slow moving targets. They get their franchise from the government. If the NSA wants weak crypto, they do weak crypto. -- Jaap-Henk Hoepman | I've got