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Bruce Schneier has changed his PGP key to 4096 bits

news.ycombinator.com

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Re: Bruce Schneier has changed his PGP key to 4096 bits

#111

Post by donniezazen »

knowtheory wrote: post #10
tptacek wrote: post #9

Or: - he really doesn't use his PGP key all that often, had the same one for 16 years on god knows how many computers, and decided that if he's going to generate a new one, he might as well send a message with it.

Normally i'd let it go, but i actually would like some clarity on your intent here. Are you implying that Schneier doesn't use encrypted communications on a regular basis, that PGP is impractical, or both? (and to be clear, my intent is not to bait, i'm actually curious)

I would like to use PGP. In my line of work folks use computers as television sets. They open browser, pdf reader, office software. I am afraid if I am to use PGP just for signing my emails it might look like spam to them.

Re: Bruce Schneier has changed his PGP key to 4096 bits

#112

Post by Kliment »

xerophtye wrote: post #109
sp332 wrote: post #101

Earlier quoted context omitted.

AES is symmetric...

exactly... I am just as confused as you are. What's the point of using AES if you are putting its key out on the open? O_O that's like using a very sophisticated lock on your front door and put up a sign saying "The key is under the Mat"

I believe the person was joking.

Re: Bruce Schneier has changed his PGP key to 4096 bits

#113

Post by fayyazkl »

BrandonY wrote: post #94
danellis wrote: post #89

Earlier quoted context omitted.

How do you securely share the AES key?

AES is really great compared to RSA, so I put my AES key on my website instead of my RSA public key. It's made it very easy for people to contact me securely.

Exactly, the same thing i am wondering. AES is symmetric. So same key is used for encryption and decryption against RSA which is asymmetric. So putting key on website is effectively the same as not encrypting at all. Did i miss any thing here?

Re: Bruce Schneier has changed his PGP key to 4096 bits

#114

Post by Qantourisc »

a--b wrote: post #81

I've been using 16,384 for my SSH key sizes for the past year and am considering using 32,768 a soon as my two year rotation period is up - would there be any problems with my key sizes?

Long key generation, longer login time, possible lack of a proper entropy in the key, if the entropy source is not good.

Re: Bruce Schneier has changed his PGP key to 4096 bits

#115

Post by mvanveen »

fayyazkl wrote: post #113
BrandonY wrote: post #94

Earlier quoted context omitted.

AES is really great compared to RSA, so I put my AES key on my website instead of my RSA public key. It's made it very easy for people to contact me securely.

Exactly, the same thing i am wondering. AES is symmetric. So same key is used for encryption and decryption against RSA which is asymmetric. So putting key on website is effectively the same as not encrypting at all. Did i miss any thing here?

just the humor

Re: Bruce Schneier has changed his PGP key to 4096 bits

#116

Post by Qantourisc »

1024 should have been save, but modern PC's can easily do 4096... So all my certificates are 4096 at the least. No reason to take a change, while there is no significant downside. So why take the risk with 1024? Maybe it's to weak, and maybe, this means we can keep our data secure for longer.

Te only reason NOT to use them: mobile end-clients, and busy server who would die from the extra CPU burden. But other then that, WHY NOT ?

Re: Bruce Schneier has changed his PGP key to 4096 bits

#117

Post by fdej »

vabmit wrote: post #104
fdej wrote: post #47

Earlier quoted context omitted.

The (public) factorization record with GNFS is 768 bits, in an effort that took about 2000 CPU years. 1024 bits is about 1000x harder, so probably within reach with government resources. 2048 bits is 10^12 times harder, which surely is out of reach for the time being time unless the NSA has a better algorithm.

Lenstra et al performed the factorization you cite, again on CPUs. Lenstra said in 2007 that he expected with in 5 years to be able to do 1024bit number - again with CPUs. 2048bit is no where near 10^12 harder if you use GPUs with larger word/op/register sizes. That's especially so with FGPAs/custom hardware with custom sized words/registers/ops. With FGPAs and custom hardware you can also locate things physically in…

10^12 is how much more work you have to do (according to the complexity estimate for the GNFS), regardless of how you do that work. If your custom-built hardware is 10^12 times faster than a general-purpose CPU, you can factor a 2048-bit number on your hardware as fast as a 768-bit number on general-purpose CPUs, but it will still take 10^12 times more work than factoring a 768-bit number on the same hardware. And I've never heard of GPUs or FPGAs giving a speedup of more than perhaps 10^4 on any problem, which still leaves a factor 10^8.

Re: Bruce Schneier has changed his PGP key to 4096 bits

#118

Post by moep »

joeyh wrote: post #73
joeyh wrote: post #67

Earlier quoted context omitted.

4096 is the largest key size gpg offers today. It was the largest key size gpg offered in 2009, which is why that's the key size I'm using now. In 1996 the largest key size pgp supported was probably 768 , which is why my first pgp key is that size. I know for sure that in 1999, the largest key I could manage to make was 2048. Looking back at those older keys, I would prefer if I could have chosen larger key sizes fo…

Seems that if you're really paranoid, gpg --gen-key --batch with an approptiate batch file can make 8192 or larger keys. Currently trying to generate a 81920 bit key, for general giggles and to increase my NSA rating.

Could you provide a sample batch file for this purpose? That’d be really helpful.
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