Re: NYC events and cell phones
[Moderator's note: I was under the impression most base stations did the crypto in hardware, so the answer would be no, no performance gain for such equipment. Besides, the main concern would be open channels, not CPU load. Anyone know better? --Perry] It's my understanding that functions like crypto find their way into a DSP, at least for North American standards. I'm also told that performance is a major reason for not supporting encryption in CDMA systems. -- Allen Ethridge [EMAIL PROTECTED] 972-758-1737 214-552-5890 - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: NYC events and cell phones
On Mon, 17 Sep 2001, Greg Rose wrote: There is one very simple reason why they might have wanted the encryption switched off. Wiretapping at the base station requires a wiretap order, whereas sniffing the airwaves in a matter of national security is something the NSA is allowed to do (but they can't get a wiretap order in a hurry). I don't know any facts in this matter at all, but I wouldn't be surprised if someone, somewhere, requested air interface encryption to be turned off. Would switching off crypto improve the performance of the base stations at all? If so, the motivation may have been less sinister. -d [Moderator's note: I was under the impression most base stations did the crypto in hardware, so the answer would be no, no performance gain for such equipment. Besides, the main concern would be open channels, not CPU load. Anyone know better? --Perry] -- | Damien Miller [EMAIL PROTECTED] \ ``E-mail attachments are the poor man's | http://www.mindrot.org / distributed filesystem'' - Dan Geer - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: NYC events and cell phones
At 01:53 AM 9/17/2001 +0100, Peter Fairbrother wrote: It is possible that damage to basestations or volume of traffic may have caused this failure. Possibly, the telco switched it off to maintain service. Equally, the FBI/NSA etc may have switched it off, but I don't know why they would bother - the encryption is only between the mobile and the basestation, and they could pick up plaintalk there much more easily. There is one very simple reason why they might have wanted the encryption switched off. Wiretapping at the base station requires a wiretap order, whereas sniffing the airwaves in a matter of national security is something the NSA is allowed to do (but they can't get a wiretap order in a hurry). I don't know any facts in this matter at all, but I wouldn't be surprised if someone, somewhere, requested air interface encryption to be turned off. Greg. Greg Rose INTERNET: [EMAIL PROTECTED] Qualcomm Australia VOICE: +61-2-9817 4188 FAX: +61-2-9817 5199 Level 3, 230 Victoria Road,http://people.qualcomm.com/ggr/ Gladesville NSW 2111232B EC8F 44C6 C853 D68F E107 E6BF CD2F 1081 A37C - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: NYC events and cell phones
At 07:59 AM 09/13/2001 -0400, Angelos D. Keromytis wrote: An interesting bit of information: on Tuesday afternoon, to the extend that cellphones operated, GSM encryption was turned off throughout Manhattan. My GSM phone would repeatedly warn me of this on every call I made (or tried to make). As of Wednesday morning, things were back to normal. Interesting. For the most part, TDMA encryption in the US isn't turned on; my Nokia phone always starts off calls by telling me Voice Privacy Not Active, even though the encryption is even lamer than the GSM encryption. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
NYC events and cell phones
An interesting bit of information: on Tuesday afternoon, to the extend that cellphones operated, GSM encryption was turned off throughout Manhattan. My GSM phone would repeatedly warn me of this on every call I made (or tried to make). As of Wednesday morning, things were back to normal. Does anyone have more details on this ? -Angelos - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
