[cryptography] London Hum Used to Timestamp Recordings
mheyman at gmail.com
mheyman at gmail.com
Fri Dec 14 05:56:29 PST 2012
>From <http://tech.slashdot.org/story/12/12/14/0229248/electrical-grid-hum-used-to-time-locate-any-digital-recording>
"It appears that the Metropolitan Police in London have been recording the
frequency of the mains supply for the past 7 years. With this,
they claim to
be able to pick up the hum from any digital recording and tell when the
recording was made. From the article: 'Comparing the unique pattern of the
frequencies on an audio recording with a database that has been logging
these changes for 24 hours a day, 365 days a year provides a digital
watermark: a date and time stamp on the recording.'"
I hope they kept that recording secret. Anybody can start recording
now and then backdate things like recorded verbal agreements.
----
-Michael Heyman
_______________________________________________
cryptography mailing list
cryptography at randombit.net
http://lists.randombit.net/mailman/listinfo/cryptography
----- End forwarded message -----
--
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
______________________________________________________________
ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE
More information about the cypherpunks-legacy
mailing list