Renesas DVB-H CA Middleware Package Enables Descrambling of Mobile TV Broadcasts

November , 2007 // Published as a news service by IHS

The new package will be available February 2008 in Japan. The package implements a descrambler function (CA: conditional access) for digital video broadcasting for handheld (DVB-H), the digital TV standard used by mobile phones in Europe.

It simplifies the process of developing applications for viewing and using encrypted fee-based content.

The package was developed in collaboration with the Systems Development Laboratory, Hitachi Ltd.

The middleware package features the following:

• A customizable modular structure. The DVB-H CA middleware package has a modular structure and provides support for four independent functions: content stream decoding, key stream decoding, authentication and decryption.

  The modular structure simplifies customization to match the desired specifications. The developer can mix and match middleware modules as required. For example, a separately developed module could be used to implement the key stream decoding function while retaining the functionality provided by the other modules in the package.

  This simplifies application development and can shorten the amount of time needed for development by approximately 30%, according to tests carried out by Renesas.

• High-performance encryption middleware. To support DVB-H CA, it is necessary to perform decryption and authentication on data encrypted in formats such as advanced encryption standard (AES) or hashed message authentication code-secure hash algorithm-1 (HMAC-SHA-1).

  The processing this entails can place a load on the CPU. The DVB-H CA middleware package is optimized along with the SH-Mobile architecture for the authentication functions and decryption, achieving a processing load, with a 512 Kbps data stream of the sort used for mobile phone TV broadcasts, of about 5 MHz for each of the functions.

  For a CPU with an operating frequency of 200 MHz, for example, this represents a processor load of only 2.5%. In addition, DVB-H CA requires that the AES key be updated frequently. This imposes a load on the CPU, but the new middleware reduces this load by making key generation processing more efficient.

  These improvements reduce the CPU load imposed by DVB-H CA functions by approximately 40%, Renesas said, contributing to a reduction in the current consumption of the entire system.

The DVB-H CA middleware package conforms to A100 service purchase and protection (SPP) under the DVB-H standard covering scrambling and unscrambling of fee-based TV broadcasts in Europe. It provides decoding functionality that supports the following content and key encryption specifications:

• Encrypted content streams conforming to secure real time protocol (SRT) and Internet Streaming Media Alliance: Encryption and Authentication Specification (ISMACryp) version 1.1.
• Key streams conforming to the A100 Annex B specification of DVB-H.

To implement this functionality, the DVB-H CA middleware package comprises a total of four middleware modules: two decode middleware modules that support two types of streams, and two encryption middleware modules. The four middleware modules are:

• Key stream decode middleware module, which analyzes the key stream and decodes and extracts the keys to be used to decode the content.
• Content stream decode middleware module, which analyzes the received content stream, obtains the decoding keys and decodes the content.
• Hash function HMAC-SHA-1 middleware module, which determines whether the key and content streams being received are proper ones.
• AES encryption middleware module, which decrypts encrypted key and content streams in 128 b block units.

Source: Renesas Technology Corp.