Re: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Hubert Kario
On Monday 03 of December 2012 12:41:10 Hauke Laging wrote: Hello, are there arguments for preferring either a) having one RSA subkey for decryption only and one for signing only or b) having only one RSA subkey for both decryption and signing? Do any problems arise with the

Re: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Hauke Laging
Am Di 04.12.2012, 13:19:11 schrieb Hubert Kario: Keys can become used up so it entirely depends on how often you use it. What I mean by that, is that any signing operation leaks some information about the key used for signing (generally far less than few tens of a bit). If you have signed

Re: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Hubert Kario
On Tuesday 04 of December 2012 14:14:34 Hauke Laging wrote: Am Di 04.12.2012, 13:19:11 schrieb Hubert Kario: Keys can become used up so it entirely depends on how often you use it. What I mean by that, is that any signing operation leaks some information about the key used for signing

Re: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Peter Lebbing
RFC 4880 says this in the Security Considerations part: * Many security protocol designers think that it is a bad idea to use a single key for both privacy (encryption) and integrity (signatures). In fact, this was one of the motivating forces behind the V4 key format with

Re: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Nicholas Cole
On Tue, Dec 4, 2012 at 12:19 PM, Hubert Kario h...@qbs.com.pl wrote: On Monday 03 of December 2012 12:41:10 Hauke Laging wrote: Hello, are there arguments for preferring either a) having one RSA subkey for decryption only and one for signing only or b) having only one RSA subkey for both

Re: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Hubert Kario
On Tuesday 04 of December 2012 16:07:26 Nicholas Cole wrote: On Tue, Dec 4, 2012 at 12:19 PM, Hubert Kario h...@qbs.com.pl wrote: On Monday 03 of December 2012 12:41:10 Hauke Laging wrote: Hello, are there arguments for preferring either a) having one RSA subkey for decryption only

Re: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Hubert Kario
On Tuesday 04 of December 2012 16:07:26 Nicholas Cole wrote: On Tue, Dec 4, 2012 at 12:19 PM, Hubert Kario h...@qbs.com.pl wrote: On Monday 03 of December 2012 12:41:10 Hauke Laging wrote: Do any problems arise with the smartcard if the same key shall do different tasks? Keys can

Fwd: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Nicholas Cole
On Tue, Dec 4, 2012 at 5:32 PM, Hubert Kario h...@qbs.com.pl wrote: On Tuesday 04 of December 2012 16:07:26 Nicholas Cole wrote: On Tue, Dec 4, 2012 at 12:19 PM, Hubert Kario h...@qbs.com.pl wrote: On Monday 03 of December 2012 12:41:10 Hauke Laging wrote: Do any problems arise with the

Fwd: Seperate RSA subkeys for decryption and signing or one for both?

2012-12-04 Thread Nicholas Cole
Meant to post this to the list. Blame gmail. -- Forwarded message -- From: Nicholas Cole nicholas.c...@gmail.com Date: Tue, Dec 4, 2012 at 7:10 PM Subject: Re: Seperate RSA subkeys for decryption and signing or one for both? To: Hubert Kario h...@qbs.com.pl How do you propose

Seperate RSA subkeys for decryption and signing or one for both?

2012-12-03 Thread Hauke Laging
Hello, are there arguments for preferring either a) having one RSA subkey for decryption only and one for signing only or b) having only one RSA subkey for both decryption and signing? Do any problems arise with the smartcard if the same key shall do different tasks? Hauke -- ☺ PGP: 7D82