A Java ring is a finger ring that contains a small microprocessor with built-in capabilities for the user, a kind of smart card that is usable on a finger. The Sun Microsystem Java Ring was introduced at its JavaOne Conference in 1998 and, instead of a gemstone, contained a cheap microprocessor in a stainless steel iButton running a Java virtual machine and preloaded with applets. The rings were built by Dallas Semiconductor. Java Ring is an extremely secure Java-powered electronic token with a continuous running, unalterable real-time clock and rugged packing, suitable for many applications. The jewel of the Java ring is the Java iButton, a microcomputer of one million single-chip transistors with a powerful Java Virtual Machine (JVM) housed in a sturdy and secure stainless steel case. Designed to be fully compatible with the Java Card 2.0 standard (for more information on Java Card 2.0, refer to the Java Developer column last month, "Understanding Java Card 2.0") the processor features a 1024-bit high-speed modular exponentiator for RSA encryption, RAM and ROM memory, and a real-time unalterable clock.
The packaged module has only one electrical contact and one ground return, according to the specifications of the Dallas Semiconductor 1-Wire bus. The non-volatile lithium-backup SRAM offers a high read / write speed and unprecedented tamper resistance through almost instantaneous removal of all memory when tempering is detected, a feature known as rapid zeroing. Data integrity and clock function are maintained for more than 10 years. The 16 mm diameter stainless steel case accommodates the largest chip sizes needed for up to 128 kilobytes of high speed non-volatile static RAM. The small, extremely sturdy packaging of the module allows you to attach the accessory of your choice to match individual lifestyles, such as a key, wallet, watch, necklace, bracelet or finger ring....