Secure MMC is a new version of the Multimedia Card developed by Infinion Technologies AG, which will support the new scheme. The announcement comes just a week after other consumer companies postponed the launch of DVD-Audio players in the wake of the cracking of the player's encryption scheme. Earlier this year, Matsushita, Toshiba and SanDisk launched their own Secure Digital Memory Card.

The Ketai de Music ("Music on Your Mobile Phone") delivery system is based on a content-protection scheme, the Universal Distribution with Access Control-Media Base (UDAC-MB). It follows a protocol standard, the Secure Multimedia Card standard and a download/playback system standards.

The companies claim the new system is the first to combine three functions in a cellular phone: voice telephony, a music downloader and a music player. Secure MMC, which will be used for music data storage, is the key component that provides strong security against the illegal duplication of data.

Security challenge

"Eighty-eight percent of young people in their 20s have portable phones and 70 to 80 percent of them also have portable audio players [in Japan], according to our survey. So we thought there could be a way to enjoy music" over the phone, said Fusao Terada, general manager of Sanyo's R&D headquarters. "Security was the key challenge." Sanyo began the project and asked Fujitsu to collaborate on security technology. Hitachi and then Infinion — Hitachi's flash memory partner — also brought their flash-card technology to the project.

Secure music distribution demands that the encryption and decryption functions be kept in a secure area. Secure MMC satisfies those requirements, and is backward-compatible with the Multimedia Card in terms of size and pin layout. The encryption and decryption functions and the license key are kept in the card's Tamper Resistant Module (TRM), which physically and logically impedes the examination or alteration of the semiconductor or the software.

Unlike conventional flash cards, "security information is stored in the tamper-resistant area and [illegal] alteration becomes impossible. And as the key is kept in the tamper-resistant area, the card has high security," said Masahiko Ogirima, senior vice president of Hitachi's semiconductor group.

Secure MMC's high data transfer rate is enabled by the addition of six pins, which are used to perform an 8-bit parallel write function. The group intends to hit 2 Mbytes/second next year and 20 Mbytes/s in 2001. With the 20-Mbyte/s transfer rate, 60 minutes of music (about 60 Mbytes) can be downloaded in 3 seconds, according to Hitachi. The high-speed download capability will enable rapid data distribution at music kiosks, which the group believes will be one important distribution route for the system.

Hitachi, Infinion and Sanyo plan to propose Secure MMC to the Multimedia Card Association as an open standard.

The UDAC-MB was originally developed for digital content in general, and not for music in particular, said Yoshiro Yoshioka, senior vice president of Fujitsu. Some features have been added for the protection of music data when it's distributed.

When a portable phone user requests a music title, the content distribution server will send back an encrypted version, and the data will be stored in the Secure MMC data area. A license key for playback is separately sent from a key distribution server and stored in the card's TRM area. A UDAC-MB decoder chip uses the key to decode the music data. "The data and key are independently handled and only the decoder chip can play the music. Even if the data is hacked halfway, it cannot be played," said Yoshioka.

UDAC-MB handles any compression scheme, so "carriers may decide on the format," he said. Fujitsu used the MP3 format to demonstrate the system.

For the time being, Sanyo will provide portable phones and Hitachi and Infinion will supply cards. Fujitsu will focus on security-related issues for servers and systems. The group is seeking to form alliances with content holders and carriers, starting first in Japan.