From mheyman@gmail.com Fri Jul 6 02:37:03 2018 From: mheyman@gmail.com To: cypherpunks-legacy@lists.cpunks.org Subject: [cryptography] London Hum Used to Timestamp Recordings Date: Fri, 06 Jul 2018 02:37:03 +0000 Message-ID: <172289279599.3881296.6776322029682799870.generated@mail.pglaf.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7417655438613408382==" --===============7417655438613408382== Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable >From "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(a)randombit.net http://lists.randombit.net/mailman/listinfo/cryptography ----- End forwarded message ----- --=20 Eugen* Leitl leitl 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 --===============7417655438613408382==--