Firewall Wizards mailing list archives
Re: R: strong encryption for Europeans
From: Martin W Freiss <freiss.pad () sni de>
Date: Tue, 25 Nov 97 20:28:03 MET
If keys are changed often enough, I think 56 bits is still pretty much ok for most uses. It depends very much on the lifetime of the data transfered versus the time needed to crack the key. If the key is changed every 15 minutes (and I assume a much stronger protection on the key exchange), then the attacker not only has to deal with finding the key, but also with finding the window in which the data he is interested in was transferred.
Well, partly. Frequent key changes guard against an attacker being able to monitor a sustained data stream, but still leaves us with (taking your example) 15 minute chunks of data that can feasibly be decrypted, one at a time, by brute force. It all boils down the old adage "cracking it must be more expensive than the worth of the data". For data of strategic importance, 56 bits is not enough. For those just wanting to safeguard against the casual snooper, and many companies I know of fall into that category, 56 bits is certainly enough. -Martin -- Martin Freiss, MF194 | freiss.pad () sni de | http://www.rmi.de/~marvin Siemens Nixdorf, CC IT Networks, Solution Team Internet/Intranet Half male, half e-mail.
Current thread:
- R: strong encryption for Europeans Franco RUGGIERI (Nov 24)
- Re: R: strong encryption for Europeans Andreas Siegert (Nov 25)
- Re: R: strong encryption for Europeans Adam Shostack (Nov 25)
- Re: R: strong encryption for Europeans Perry E. Metzger (Nov 25)
- Re: R: strong encryption for Europeans Adam Shostack (Nov 25)
- Re: R: strong encryption for Europeans Adam Shostack (Nov 25)
- Re: R: strong encryption for Europeans Martin W Freiss (Nov 25)
- Re: R: strong encryption for Europeans Andreas Siegert (Nov 25)
- Re: R: strong encryption for Europeans Arjo Mukherjee (Nov 25)
- Re: R: strong encryption for Europeans Bennett Todd (Nov 25)
- Re: R: strong encryption for Europeans Ted Doty (Nov 25)
- <Possible follow-ups>
- Re: R: strong encryption for Europeans Chris Lonvick (Nov 24)
- Re: R: strong encryption for Europeans lum (Nov 25)
- Re: R: strong encryption for Europeans Bennett Todd (Nov 25)
- Re: R: strong encryption for Europeans lum (Nov 25)