Re: Best practice for periodic key change?

2011-05-10 Thread Jerome Baum
On Tue, May 10, 2011 at 07:42, Grant Olson k...@grant-olson.net wrote: On 5/10/2011 1:35 AM, Jerome Baum wrote: AFAIK, the CAs over here will just supply a card. There is no question of whether the key is generated on-card or not -- the CA confirms this implicitly with their certification

Re: Best practice for periodic key change?

2011-05-10 Thread Jerome Baum
On Tue, May 10, 2011 at 07:42, Grant Olson k...@grant-olson.net wrote: Okay, yeah, if the CA sets up the card, authenticates it with their signing key, and ships it to you, then there would never be a separate master key, no problem there. I get the feeling the card won't like it if you try

Re: Best practice for periodic key change?

2011-05-10 Thread Hauke Laging
Am Dienstag, 10. Mai 2011, 07:10:42 schrieb Jerome Baum: an option for GnuPG: reject-subkey-signatures No need to change OpenPGP for this. This is possible only if it is safe for old implementations. I see one option for that: A signature notation for this purpose could be defined and this

Re: Best practice for periodic key change?

2011-05-10 Thread Jerome Baum
I don't see why it would need a standards change, or why the option can't be, well, optional. We aren't trying to force all gpg installations to conform, but to make it possible to configure an installation to conform. Normal gpg should continue to function. (Mobile/Handy) Am 10.05.2011 15:33

Re: Best practice for periodic key change?

2011-05-09 Thread Hauke Laging
Am Sonntag, 8. Mai 2011, 14:50:36 schrieb MFPA: Mainly the key's owner, but could also protect others from relying on signatures from a compromised key for which they have not received a revocation certificate. Right. The problem: Protection you don't know of. So seriously this additional

Re: Best practice for periodic key change?

2011-05-09 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Monday 9 May 2011 at 5:09:00 PM, in mid:201105091809.05423.mailinglis...@hauke-laging.de, Hauke Laging wrote: Am Sonntag, 8. Mai 2011, 14:50:36 schrieb MFPA: Mainly the key's owner, but could also protect others from relying on

Re: Best practice for periodic key change?

2011-05-09 Thread Hauke Laging
Am Montag, 9. Mai 2011, 19:51:12 schrieb MFPA: Could that be a form of attack? Bob and Mallory sign a contract of some kind - it transpires the contract benefits Bob - Mallory tries to make it look as if Bob had not signed. That would not work for several reasons which arise not from

Re: Best practice for periodic key change?

2011-05-09 Thread Jerome Baum
On Mon, May 9, 2011 at 18:09, Hauke Laging mailinglis...@hauke-laging.dewrote: IMHO there are only two possibilities for making (a new version of) OpenPGP signature law compatible: a) The CA creates a mainkey and subkeys. The mainkey is destroyed immediately afterwards. That might be

Re: Best practice for periodic key change?

2011-05-09 Thread Daniel Kahn Gillmor
On 05/10/2011 12:01 AM, Jerome Baum wrote: c) Program the smart-card so it doesn't sign sub-keys? I'm not familiar with the internals of smart-card implementations but the OpenPGP sub-key signatures are of a different type than the data signatures. The smart-card can probably recognize if it's

Re: Best practice for periodic key change?

2011-05-09 Thread Daniel Kahn Gillmor
On 05/10/2011 12:32 AM, Jerome Baum wrote: Is that an implementation problem? i.e. is it possible to write an implementation that does distinguish, or is it technically impossible w/out processing the entire data on-card? As i understand the process, i think it would be necessary to pass all

Re: Best practice for periodic key change?

2011-05-09 Thread Grant Olson
On 5/10/2011 12:41 AM, Daniel Kahn Gillmor wrote: On 05/10/2011 12:32 AM, Jerome Baum wrote: Is that an implementation problem? i.e. is it possible to write an implementation that does distinguish, or is it technically impossible w/out processing the entire data on-card? As i understand the

Re: Best practice for periodic key change?

2011-05-09 Thread Jerome Baum
On Tue, May 10, 2011 at 07:01, Grant Olson k...@grant-olson.net wrote: On 5/10/2011 12:41 AM, Daniel Kahn Gillmor wrote: Maybe one of the folks with experience implementing these devices can give more concrete details? I can confirm. The cards only get the hash and sign that. The trouble

Re: Best practice for periodic key change?

2011-05-09 Thread Grant Olson
On 5/10/2011 1:10 AM, Jerome Baum wrote: On Tue, May 10, 2011 at 07:01, Grant Olson k...@grant-olson.net mailto:k...@grant-olson.net wrote: On 5/10/2011 12:41 AM, Daniel Kahn Gillmor wrote: Maybe one of the folks with experience implementing these devices can give more

Re: Best practice for periodic key change?

2011-05-09 Thread Jerome Baum
On Tue, May 10, 2011 at 07:30, Grant Olson k...@grant-olson.net wrote: But there's no way to prove that the keys were originally generated on-card, and weren't imported from a software private key where there was never a separate master certification key. AFAIK, the CAs over here will just

Re: Best practice for periodic key change?

2011-05-09 Thread Grant Olson
On 5/10/2011 1:35 AM, Jerome Baum wrote: On Tue, May 10, 2011 at 07:30, Grant Olson k...@grant-olson.net mailto:k...@grant-olson.net wrote: But there's no way to prove that the keys were originally generated on-card, and weren't imported from a software private key where there

Re: Best practice for periodic key change?

2011-05-08 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Sunday 8 May 2011 at 3:34:52 AM, in mid:201105080434.57614.mailinglis...@hauke-laging.de, Hauke Laging wrote: There is probability but no safety in this assumption. I have no idea what is the probability. I have seen no figures relating

Re: Best practice for periodic key change?

2011-05-08 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Sunday 8 May 2011 at 3:21:41 AM, in mid:4dc5fe35.5080...@sixdemonbag.org, Robert J. Hansen wrote: The trial court ruled in favor of the farmers. I remember literature from my bank saying that cheques did not need to be on their printed

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sat, May 7, 2011 at 04:33, Grant Olson k...@grant-olson.net wrote: On 5/6/2011 10:05 PM, Hauke Laging wrote: Several people have mentioned that a signature does not become invalid by expiration of the key. That is formally correct an describes the GnuPG behaviour. But with regard to

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sat, May 7, 2011 at 01:43, MFPA expires2...@ymail.com wrote: On Saturday 7 May 2011 at 12:11:06 AM, in mid:BANLkTimNq9nxpf23=pe2n0rr1stnh3a...@mail.gmail.com, Jerome Baum wrote: Say my sub-key expired yesterday. Today, you come up to me and ask me to sign something (say, a statement

Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 1:09:25 PM, in mid:banlktimpo-bwz38icrfc-cudrkh968f...@mail.gmail.com, Jerome Baum wrote: Then I would say it is the recipients responsibility to only accept reasonable signatures. Fair enough. Reasonable is

Re: Best practice for periodic key change?

2011-05-07 Thread Hauke Laging
Am Samstag, 7. Mai 2011, 15:54:21 schrieb MFPA: and since the cost is so low, that there is no point in not having them (assuming, of course, that you separate master and sub-keys). You can't assume. You can very well if you don't claim that for all cases but use this assumption for

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sat, May 7, 2011 at 15:54, MFPA expires2...@ymail.com wrote: (snip huge email) Next time can you read the whole email and reply to it as a whole? As for signature checking, I stand by my point: Over here, signing a document today and claiming on the signature that it was signed tomorrow is

Re: Best practice for periodic key change?

2011-05-07 Thread Jean-David Beyer
Jerome Baum wrote: On Sat, May 7, 2011 at 15:54, MFPA expires2...@ymail.com mailto:expires2...@ymail.com wrote: (snip huge email) Next time can you read the whole email and reply to it as a whole? As for signature checking, I stand by my point: Over here, signing a document today

[OT] Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
Hey not that any of this relates to the original question on digital signatures, but interesting nonetheless so I guess let's keep it on the list as OT. On Sat, May 7, 2011 at 19:16, Jean-David Beyer jeandav...@verizon.netwrote: When I was on a grand jury, the prosecutor said that while the

Re: [OT] Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 6:42:06 PM, in mid:BANLkTi=-c_xijtne7+qyrlv06fj2d7z...@mail.gmail.com, Jerome Baum wrote: Hey not that any of this relates to the original question on digital signatures, but interesting nonetheless so I guess

Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 4:03:19 PM, in mid:BANLkTi=ergk72zxrb46dwkc_dim0etg...@mail.gmail.com, Jerome Baum wrote: Next time can you read the whole email and reply to it as a whole? It's generally better to read the whole email and then

Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 3:06:16 PM, in mid:201105071606.21732.mailinglis...@hauke-laging.de, Hauke Laging wrote: Am Samstag, 7. Mai 2011, 15:54:21 schrieb MFPA: You can't assume. You can very well if you don't claim that for all cases

Re: Best practice for periodic key change?

2011-05-07 Thread Grant Olson
On 5/7/2011 7:54 AM, Hauke Laging wrote: Am Samstag, 7. Mai 2011, 04:33:17 schrieb Grant Olson: 1) I digitally sign a document saying I owe you money. The signing key has an expiration date. 2) Key expires. I do nothing. 3) The original document is invalidated. I no longer owe you

Re: [OT] Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 8:50:45 PM, in mid:BANLkTi=tg4z7mkwtnztwlhpjmhffznw...@mail.gmail.com, Jerome Baum wrote: We weren't talking about fraud and deception. Only about lying -- rather, telling an untruth, which you may or may not be

Re: Best practice for periodic key change?

2011-05-07 Thread Ingo Klöcker
On Friday 06 May 2011, MFPA wrote: Hi On Friday 6 May 2011 at 8:48:03 PM, in mid:201105062148.04...@thufir.ingo-kloecker.de, Ingo Klöcker wrote: Unless I'm missing something the difference is as follows: - With prolongation of the expiration time releases signed before the

Re: [OT] Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sat, May 7, 2011 at 22:47, Jerome Baum jer...@jeromebaum.com wrote: On Sat, May 7, 2011 at 22:38, MFPA expires2...@ymail.com wrote: As for the meaning of the date, whether it is supposed to mean the date the signature was written or the date the instruction to pay becomes effective or

Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 9:52:51 PM, in mid:BANLkTi=nwtmcchq96olpkhdmovunsoq...@mail.gmail.com, Jerome Baum wrote: I don't think you get what kind of assumption we are talking about. There are two kinds: 1. I assume something is generally

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sat, May 7, 2011 at 23:07, MFPA expires2...@ymail.com wrote: On Saturday 7 May 2011 at 9:52:51 PM, in mid:BANLkTi=nwtmcchq96olpkhdmovunsoq...@mail.gmail.com, Jerome Baum wrote: I don't think you get what kind of assumption we are talking about. There are two kinds: 1. I assume

Re: Best practice for periodic key change?

2011-05-07 Thread Ingo Klöcker
On Saturday 07 May 2011, MFPA wrote: Hi On Friday 6 May 2011 at 10:18:29 PM, in mid:banlktin2w8ljxyghv3_5npfbsibhrp9...@mail.gmail.com, Jerome Baum wrote: If my key expired yesterday, no-one can forge a message with that key and claim it's from today. Never heard of a system

Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 9:56:14 PM, in mid:201105072256.15...@thufir.ingo-kloecker.de, Ingo Klöcker wrote: It depends on your definition of valid. In my book a signature can only be valid if the corresponding key is valid. Expired keys

Re: Best practice for periodic key change?

2011-05-07 Thread Ingo Klöcker
On Sunday 08 May 2011, Grant Olson wrote: === You seem to send messages from the future. ;-) On 5/6/11 3:48 PM, Ingo Klöcker wrote: On Thursday 05 May 2011, Hauke Laging wrote: What is the difference between these two options with respect to the point of confusion?

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
2011/5/7 Ingo Klöcker kloec...@kde.org This explains why digital signatures with legally binding date often (always?) require a timestamp by a certified third party. Not always (every statement of intent is binding, even w/out a notary), but e.g. over here (Germany) for a digital signature to

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
2011/5/7 MFPA expires2...@ymail.com On Saturday 7 May 2011 at 9:56:14 PM, in mid:201105072256.15...@thufir.ingo-kloecker.de, Ingo Klöcker wrote: It depends on your definition of valid. In my book a signature can only be valid if the corresponding key is valid. Expired keys are not

Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 10:21:17 PM, in mid:banlktinacqcd+mz7fl1thlk55x2+u9g...@mail.gmail.com, Jerome Baum wrote: On digital signatures being legally binding, apparently a scanned bitmap of your signature is enough to be binding (as

Re: Best practice for periodic key change?

2011-05-07 Thread Robert J. Hansen
On 05/07/2011 02:49 PM, MFPA wrote: What is to stop that scanned bitmap of a person's signature being applied to a document the individual has no knowledge about? Nothing. That's the nature of physical signatures. A physical signature binds tightly to the individual (handwriting being hard to

Re: Best practice for periodic key change?

2011-05-07 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 10:22:33 PM, in mid:banlktimrobi47ottgokkveeoh-ayroo...@mail.gmail.com, Jerome Baum wrote: Definitely. I get his point about rejecting them entirely though, as it is (and that's what this dicussion is all about)

Re: Best practice for periodic key change?

2011-05-07 Thread Grant Olson
On 5/7/2011 5:08 PM, Ingo Klöcker wrote: On Sunday 08 May 2011, Grant Olson wrote: === You seem to send messages from the future. ;-) That's funny. I wanted to make sure I wasn't lying before replying. A little later I was deploying code to some servers. After the update

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sun, May 8, 2011 at 03:13, Jerome Baum jer...@jeromebaum.com wrote: On Sat, May 7, 2011 at 23:56, Robert J. Hansen r...@sixdemonbag.orgwrote: On 05/07/2011 02:49 PM, MFPA wrote: What is to stop that scanned bitmap of a person's signature being applied to a document the individual has no

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sat, May 7, 2011 at 23:56, Robert J. Hansen r...@sixdemonbag.org wrote: On 05/07/2011 02:49 PM, MFPA wrote: What is to stop that scanned bitmap of a person's signature being applied to a document the individual has no knowledge about? Nothing. That's the nature of physical signatures.

Re: Best practice for periodic key change?

2011-05-07 Thread David Shaw
On May 7, 2011, at 5:49 PM, MFPA wrote: On Saturday 7 May 2011 at 10:21:17 PM, in mid:banlktinacqcd+mz7fl1thlk55x2+u9g...@mail.gmail.com, Jerome Baum wrote: On digital signatures being legally binding, apparently a scanned bitmap of your signature is enough to be binding (as would be no

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sun, May 8, 2011 at 03:50, David Shaw ds...@jabberwocky.com wrote: Incidentally, speaking of bitmap signatures - a signature made via a rubber stamp of a signature can be binding under certain circumstances as well (at least in the US - I don't know about elsewhere). Often enough you

Re: Best practice for periodic key change?

2011-05-07 Thread Robert J. Hansen
On 05/07/2011 09:50 PM, David Shaw wrote: Incidentally, speaking of bitmap signatures - a signature made via a rubber stamp of a signature can be binding under certain circumstances as well (at least in the US - I don't know about elsewhere). Within the U.S., the standard doesn't involve

Re: Best practice for periodic key change?

2011-05-07 Thread Hauke Laging
Am Samstag, 7. Mai 2011, 21:43:38 schrieb MFPA: At what point does it become safe to assume that an individual with expiry dates on their subkeys keeps their master key securely offline? There is probability but no safety in this assumption. But it this relevant? How and whom is an expiration

Re: Best practice for periodic key change?

2011-05-07 Thread David Shaw
On May 7, 2011, at 10:21 PM, Robert J. Hansen wrote: On 05/07/2011 09:50 PM, David Shaw wrote: Incidentally, speaking of bitmap signatures - a signature made via a rubber stamp of a signature can be binding under certain circumstances as well (at least in the US - I don't know about

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sun, May 8, 2011 at 00:07, MFPA expires2...@ymail.com wrote: Maybe we could use something like http://www.itconsult.co.uk/stamper.htm I checked the newsgroup (only through Google, last posting from '05) and don't see the signatures being posted anymore. Can anyone confirm this? -- Jerome

Re: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
On Sun, May 8, 2011 at 04:53, David Shaw ds...@jabberwocky.com wrote: I knew a man (a lawyer, as it happened) who always signed documents with several loops in a row. When I asked him why he didn't use a real signature (i.e. why he didn't sign his name), he just grinned and said Who's to say

Re: Best practice for periodic key change?

2011-05-07 Thread David Shaw
On May 7, 2011, at 10:57 PM, Jerome Baum wrote: On Sun, May 8, 2011 at 00:07, MFPA expires2...@ymail.com wrote: Maybe we could use something like http://www.itconsult.co.uk/stamper.htm I checked the newsgroup (only through Google, last posting from '05) and don't see the signatures being

Re: Best practice for periodic key change?

2011-05-07 Thread David Shaw
On May 7, 2011, at 11:04 PM, Jerome Baum wrote: On Sun, May 8, 2011 at 04:53, David Shaw ds...@jabberwocky.com wrote: I knew a man (a lawyer, as it happened) who always signed documents with several loops in a row. When I asked him why he didn't use a real signature (i.e. why he didn't

Fwd: Best practice for periodic key change?

2011-05-07 Thread Jerome Baum
Shaw ds...@jabberwocky.com Date: Sun, May 8, 2011 at 05:15 Subject: Re: Best practice for periodic key change? To: Jerome Baum jer...@jeromebaum.com Cc: MFPA expires2...@ymail.com, Jerome Baum on GnuPG-Users gnupg-users@gnupg.org On May 7, 2011, at 10:57 PM, Jerome Baum wrote: On Sun, May 8, 2011

Re: Best practice for periodic key change?

2011-05-06 Thread Jeffrey Walton
On Thu, May 5, 2011 at 4:10 PM, Doug Barton do...@dougbarton.us wrote: On 05/04/2011 23:52, Andreas Heinlein wrote: We have a OpenPGP key which we use for signing our software releases. That key should be changed yearly and carry an expiration date to enforce this change. What are you

Re: Best practice for periodic key change?

2011-05-06 Thread Andreas Heinlein
Am 05.05.2011 22:10, schrieb Doug Barton: On 05/04/2011 23:52, Andreas Heinlein wrote: We have a OpenPGP key which we use for signing our software releases. That key should be changed yearly and carry an expiration date to enforce this change. What are you trying to accomplish by doing it

Re: Best practice for periodic key change?

2011-05-06 Thread Doug Barton
On 05/05/2011 23:22, Andreas Heinlein wrote: Like Werner said, many people never refresh their keys, so expiring is indeed a way to force them to do that. ( I admit that, in our case, even this will not help, since gpg will happily verify a signature made by an expired key. It will tell you that

Re: Best practice for periodic key change?

2011-05-06 Thread Daniel Kahn Gillmor
On 05/06/2011 03:47 AM, Doug Barton wrote: There's also another element, the expiration date is irrelevant if the key is actually compromised. If Eve has your secret key she can simply update or remove the expiration date, and upload the new version of the public key to the public keyservers.

Re: Best practice for periodic key change?

2011-05-06 Thread Hauke Laging
Am Freitag, 6. Mai 2011, 09:47:57 schrieb Doug Barton: There's also another element, the expiration date is irrelevant if the key is actually compromised. If Eve has your secret key she can simply update or remove the expiration date, and upload the new version of the public key to the public

Re: Best practice for periodic key change?

2011-05-06 Thread Ingo Klöcker
On Thursday 05 May 2011, Hauke Laging wrote: Am Donnerstag, 5. Mai 2011, 11:19:30 schrieb Werner Koch: A period key change is problematic because it confuses those who want to verify the signatures. BTW, the prolongation of the expiration time has showed (by means of a lot of

Re: Best practice for periodic key change?

2011-05-06 Thread Doug Barton
On 05/06/2011 08:34, Hauke Laging wrote: Am Freitag, 6. Mai 2011, 09:47:57 schrieb Doug Barton: There's also another element, the expiration date is irrelevant if the key is actually compromised. If Eve has your secret key she can simply update or remove the expiration date, and upload the new

Re: Best practice for periodic key change?

2011-05-06 Thread Jerome Baum
On Fri, May 6, 2011 at 22:37, Doug Barton do...@dougbarton.us wrote: I don't understand this response. What I'm saying is that if the key is compromised, expiration dates become irrelevant. Up to a point. If my key expired yesterday, no-one can forge a message with that key and claim it's

Re: Best practice for periodic key change?

2011-05-06 Thread Grant Olson
On 5/6/11 4:48 PM, Jerome Baum wrote: On Fri, May 6, 2011 at 22:37, Doug Barton do...@dougbarton.us mailto:do...@dougbarton.us wrote: I don't understand this response. What I'm saying is that if the key is compromised, expiration dates become irrelevant. Up to a point. If my

Re: Best practice for periodic key change?

2011-05-06 Thread Doug Barton
On 05/06/2011 13:48, Jerome Baum wrote: On Fri, May 6, 2011 at 22:37, Doug Barton do...@dougbarton.us mailto:do...@dougbarton.us wrote: I don't understand this response. What I'm saying is that if the key is compromised, expiration dates become irrelevant. Up to a point. If my key

Re: Best practice for periodic key change?

2011-05-06 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Friday 6 May 2011 at 8:48:03 PM, in mid:201105062148.04...@thufir.ingo-kloecker.de, Ingo Klöcker wrote: Unless I'm missing something the difference is as follows: - With prolongation of the expiration time releases signed before the

Re: Best practice for periodic key change?

2011-05-06 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Friday 6 May 2011 at 9:48:26 PM, in mid:banlktim3-dgy2ngvetevfjsxng8m5c2...@mail.gmail.com, Jerome Baum wrote: If my key expired yesterday, no-one can forge a message with that key and claim it's from today. Never heard of a system

Fwd: Re: Best practice for periodic key change?

2011-05-06 Thread Grant Olson
Meant to sent on-list... Original Message Subject: Re: Best practice for periodic key change? Date: Sun, 08 May 2011 16:39:34 -0400 From: Grant Olson k...@grant-olson.net To: Ingo Klöcker kloec...@kde.org On 5/6/11 3:48 PM, Ingo Klöcker wrote: On Thursday 05 May 2011, Hauke

Re: Best practice for periodic key change?

2011-05-06 Thread Jerome Baum
On Fri, May 6, 2011 at 23:07, MFPA expires2...@ymail.com wrote: On Friday 6 May 2011 at 9:48:26 PM, in mid:banlktim3-dgy2ngvetevfjsxng8m5c2...@mail.gmail.com, Jerome Baum wrote: If my key expired yesterday, no-one can forge a message with that key and claim it's from today. Never

Re: Best practice for periodic key change?

2011-05-06 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Friday 6 May 2011 at 10:18:29 PM, in mid:banlktin2w8ljxyghv3_5npfbsibhrp9...@mail.gmail.com, Jerome Baum wrote: If my key expired yesterday, no-one can forge a message with that key and claim it's from today. Never heard of a system

Re: Best practice for periodic key change?

2011-05-06 Thread Jerome Baum
On Sat, May 7, 2011 at 00:40, MFPA expires2...@ymail.com wrote: On Friday 6 May 2011 at 10:18:29 PM, in mid:banlktin2w8ljxyghv3_5npfbsibhrp9...@mail.gmail.com, Jerome Baum wrote: If my key expired yesterday, no-one can forge a message with that key and claim it's from today. Suppose

Re: Best practice for periodic key change?

2011-05-06 Thread Jerome Baum
On Sat, May 7, 2011 at 01:01, Jerome Baum jer...@jeromebaum.com wrote: Okay, let me rephrase that. claim it's from today should have been have the signature date as today. That's how I would interpret such a claim. Email headers don't really make a difference -- they would have signed it

Re: Best practice for periodic key change?

2011-05-06 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 12:11:06 AM, in mid:BANLkTimNq9nxpf23=pe2n0rr1stnh3a...@mail.gmail.com, Jerome Baum wrote: Actually let me put this in context so you see what I mean. I already see what you mean; I just happen to disagree. (-;

Re: Best practice for periodic key change?

2011-05-06 Thread MFPA
-BEGIN PGP SIGNED MESSAGE- Hash: SHA512 Hi On Saturday 7 May 2011 at 12:01:30 AM, in mid:banlktik+i0ml2fozkzbzpt+ykoojycs...@mail.gmail.com, Jerome Baum wrote: Email headers don't really make a difference -- they would have signed it yesterday and sent it today, but the message is

Re: Best practice for periodic key change?

2011-05-06 Thread Hauke Laging
Am Freitag, 6. Mai 2011, 21:48:03 schrieb Ingo Klöcker: What is the difference between these two options with respect to the point of confusion? Unless I'm missing something the difference is as follows: - With prolongation of the expiration time releases signed before the prolongation

Re: Best practice for periodic key change?

2011-05-06 Thread Hauke Laging
Am Freitag, 6. Mai 2011, 22:37:12 schrieb Doug Barton: That's not correct for subkeys and offline mainkeys as the good guys do it. I don't understand this response. What I'm saying is that if the key is compromised, expiration dates become irrelevant. Perhaps you could expand your

Re: Best practice for periodic key change?

2011-05-06 Thread Grant Olson
On 5/6/2011 10:05 PM, Hauke Laging wrote: Several people have mentioned that a signature does not become invalid by expiration of the key. That is formally correct an describes the GnuPG behaviour. But with regard to content in such a case there has to be an additional proof that the

Best practice for periodic key change?

2011-05-05 Thread Andreas Heinlein
Hello, I hope you can give me some advice on the following problem: We have a OpenPGP key which we use for signing our software releases. That key should be changed yearly and carry an expiration date to enforce this change. However, for the signatures to be useful, the key has to be signed by

Re: Best practice for periodic key change?

2011-05-05 Thread Werner Koch
On Thu, 5 May 2011 08:52, aheinl...@gmx.com said: We have a OpenPGP key which we use for signing our software releases. That key should be changed yearly and carry an expiration date to enforce this change. However, for the signatures to be useful, the key has to be signed by quite a lot of

Re: Best practice for periodic key change?

2011-05-05 Thread Hauke Laging
Am Donnerstag, 5. Mai 2011, 11:19:30 schrieb Werner Koch: A period key change is problematic because it confuses those who want to verify the signatures. BTW, the prolongation of the expiration time has showed (by means of a lot of complaining mails) that many folks don't refresh the key

Re: Best practice for periodic key change?

2011-05-05 Thread Werner Koch
On Thu, 5 May 2011 17:07, mailinglis...@hauke-laging.de said: Are there people who check the subkey IDs of old and new signatures, get confused by a change despite of gpg saying it's all right (which IMHO demands they have not understood the concept of subkeys)? No they are confused that I

Re: Best practice for periodic key change?

2011-05-05 Thread John Clizbe
Hauke Laging wrote: BTW: Would it be a good idea for gpg to suggest the user to check for an updated version of the key (or do it automatically before if configured to do so) if it find an expired subkey? This would probably not work with the GUIs though (but might make the GUI developers

Re: Best practice for periodic key change?

2011-05-05 Thread Grant Olson
On 5/5/11 2:52 AM, Andreas Heinlein wrote: Hello, I hope you can give me some advice on the following problem: We have a OpenPGP key which we use for signing our software releases. That key should be changed yearly and carry an expiration date to enforce this change. However, for the

Re: Best practice for periodic key change?

2011-05-05 Thread Doug Barton
On 05/04/2011 23:52, Andreas Heinlein wrote: We have a OpenPGP key which we use for signing our software releases. That key should be changed yearly and carry an expiration date to enforce this change. What are you trying to accomplish by doing it this way? I've yet to see a good rationale