AES (Advanced Encryption Standard) encryption technology employing a 256-bit key was approved in the US as a government standard encryption algorithm in 2001 [FIPS 197]. The CTR (Counter) Encryption mode as found in the new Lectrosonics Digital Secure Wireless system maintains low latency (2.5 ms overall) while keeping channel noise at a minimum. Key management is user selectable in one of two modes: "persistent", where the key is kept from session to session, and "one-time", where the key must be generated for each session (most secure).
The system utilises a special chip for entropy generation in order to ensure the key is generated in a truly random manner-thus complying with another US government standard [FIPS 140-2]. The key transfer requires a simple cabled download, thus avoiding security issues with easily detected infrared key transfer systems.
The new Lectrosonics Digital Secure Wireless system consists of the DR digital wireless receiver frame, the individual DRM digital receiver modules, and the DB digital wireless beltpack transmitter. Similar in form to Lectrosonics' popular Venue receiver systems, the DR digital wireless receiver frame supports up to 6 channels / modules in 1RU. Analogue and digital (AES/EBU) XLR outputs are selectable on the device menu. The frame supports wideband reception (470.100 to 691.175 MHz), 50 Ohm BNC antenna inputs, and outputs for cascading up to 3 additional frames (24 channels total) on one set of antennas, without an external multi-coupler. The clock input and output enables the DR to be the master clock in a digital audio system or to be the slave to an external master clock. A ΒΌ-inch headphone output can be fed from a mixture of channel signals, or from isolated channels.
The DRM digital receiver module docks into the DR digital wireless receiver frame and up to six modules can be docked per a single DR frame. Each receiver module has a 25.5 MHz bandwidth. The new DRM digital receiver modules are available on all standard Lectrosonics frequency blocks.
The Lectrosonics DB digital wireless beltpack transmitter features wideband tuning (470-698 MHz), a highly linear RF output stage for reduced intermodulation distortion and for this reason, high channel counts are possible even with minimum RF spectrum available.
Karl Winkler, Lectrosonics' director of business development, offered these comments regarding the company's new system, "The new Digital Secure Wireless system is the ideal tool for those environments where privacy is crucial and is, for example, particularly well-suited for use at large corporations, banks and other financial institutions.
"With the passage in 2002 of the Sarbanes-Oxley Act, information security and access control have been central themes with companies in compliance with the law. Closed sets, theater and live productions can similarly benefit from secure wireless mic transmission. Our new Digital Secure Wireless system provides the convenience of wireless freedom while protecting one's sensitive information."
(Jim Evans)
