01-04-2010, 11:52 AM
1. Introduction
Java Ring is a secure, durable, wearable Java-powered electronic token. It is a tiny wearable computer with 6 kilobytes of RAM. 6 K is enough to hold your secret codes, your credit cards numbers, your driver license, other wallet contents, and even some electronic cash. The ring can also store a few important URLs. Indeed, one of the current Java Ring demos is the ability for us to walk up to any computer in the world that has a Java Ring reader and have our home page loaded simply by touching the ring to the reader .
From a user interface perspective, one can also hope that future rings will be designed by jewelry designers and look less nerdy. Also, it would be possible to gain the same functionality in a watch or a belt buckle. The key issue about a wearable computer is not whether it is a ring or another form factor: The deciding point is that you will always have it with you. Many aspects of computing change once there is no need to go to a special room to get at the computer. It's in the details the Java Ring is an extremely secure Java-powered electronic token with a continuously running, unalterable real-time clock and rugged packaging, suitable for many applications.
The jewel of the Java Ring is the Java iButton -- a one-million transistor, single-chip trusted microcomputer with a powerful Java virtual machine (JVM) housed in a rugged and secure stainless-steel case. Designed to be fully compatible with the Java Card 2.0 standard. The processor features a high-speed 1024-bit modular exponentiator for RSA encryption, large RAM and ROM memory capacity, and an unalterable realtime clock. The packaged module has only a single electrical contact and a ground return, conforming to the specifications of the Dallas Semiconductor 1-Wire bus. Lithium-backed non-volatile SRAM offers high read/write speed and unparalleled tamper resistance through near-instantaneous clearing of all memory when tempering is detected, a feature known as rapid zeroization. Data integrity and clock function are maintained for more than 10 years. The 16-millimeter diameter stainless steel enclosure accommodates the larger chip sizes needed for up to 128 kilobytes of high-speed nonvolatile static RAM. The small and extremely rugged packaging of the module allows it to attach to the accessory of your choice to match individual lifestyles, such as a key fob, wallet, watch, necklace, bracelet, or finger ring.
2. Historical background
In the summer of 1989, Dallas Semiconductor Corp. produced the first stainless-steel-encapsulated memory devices utilizing the Dallas Semiconductor 1-Wire communication protocol. By 1990, this protocol had been refined and employed in a variety of self-contained memory devices. Originally called "touch memory" devices, they were later renamed "iButtons." Packaged like batteries, iButtons have only a single active electrical contact on the top surface, with the stainless steel shell serving as ground.
Data can be read from or written to the memory serially through a simple and inexpensive RS232C serial port adapter, which also supplies the power required to perform the I/O. The iButton memory can be read or written with a momentary contact to the "Blue Dot" receptor provided by the adapter. When not connected to the serial port adapter, memory data is maintained in non-volatile random access memory (NVRAM) by a lifetime lithium energy supply that will maintain the memory content for at least 10 years. Unlike electrically erasable programmable read-only memory (EEPROM), the NVRAM iButton memory can be erased and rewritten as often as necessary without wearing out. It can also be erased or rewritten at the high speeds typical of complementary metal oxide semiconductor (CMOS) memory, without requiring the time-consuming programming of EEPROM.
Since their introduction, iButton memory devices have been deployed in vast quantities as rugged portable data carriers, often in harsh environmental conditions. Among the large-scale uses are as transit fare carriers in Istanbul, Turkey; as maintenance record carriers on the sides of Ryder trucks; and as mailbox identifiers inside the mail compartments of the U.S. Postal Service's outdoor mailboxes. They are worn as earrings by cows in Canada to hold vaccination records, and they are used by agricultural workers in many areas as rugged substitutes for timecards.
Every iButton product is manufactured with a unique 8-byte serial number and carries a guarantee that no two parts will ever have the same number. Among the simplest iButtons are memory devices that can hold files and subdirectories and can be read and written like small floppy disks. In addition to these, there are iButtons with password-protected file areas for security applications, iButtons that count the number of times they have been rewritten for securing financial transactions, iButtons with temperature sensors, iButtons with continuously running date/time clocks, and even iButtons containing powerful microprocessors.
3. The postal security device
For over 10 years, Dallas Semiconductor also has been designing, making, and selling a line of highly secure microprocessors that are used in satellite TV descramblers, automatic teller machines, point-of-sale terminals, and other similar applications requiring cryptographic security and high resistance to attack by hackers. The U.S. Postal Service's (USPS) Information Based Indicia Program Postal Security Device Specification, intended to permit printing of valid U.S. postage on any PC, provided the first opportunity to combine two areas of expertise when a secure microprocessor was designed into an iButton.
The resulting product, named the Crypto iButton, combines high processor performance, high-speed cryptographic primitives, and exceptional protection against physical and cryptographic attack.
For example, the large integer modular exponentiation engine can perform 1024-bit modular exponentiations with a 1024-bit exponent in significantly less than a second. The ability to perform large integer modular exponentiations at high speed is central to RSA encryption, Diffie-Hellman key exchange, Digital Signature Standard (FIPS 186), and many other modern cryptographic operations.
An agreement between Dallas Semiconductor and RSA Data Security Inc. provides a paid-up license for anyone using the Crypto iButton to perform RSA encryption and digital signatures so that no further licensing of the RSA encryption technology is required. High security is afforded by the ability to erase the contents of NVRAM extremely quickly. This feature, rapid zeroization, is a requirement for high security devices that may be subjected to attacks by hackers. As a result of its high security, the Crypto iButton is expected to win the FIPS 140-1 security certification by the National Institute of Standards and Technology (NIST).
A special operating system was designed and stored in the ROM of the Crypto iButton to support cryptography and general-purpose financial transactions -- such as those required by the Postal Service program. While not a Java virtual machine, the E-Commerce firmware designed for this application had several points of similarity with Java, including an object-oriented design and a bytecode interpreter to interpret and execute Dallas Semiconductor's custom-designed E-Commerce Script Language.
A compiler was also written to compile the high-level language representation of the Script Language to a bytecode form that could be interpreted by the E-Commerce VM. Although the E-Commerce firmware was intended primarily for the USPS application, the firmware supports a variety of general electronic commerce models that are suitable for many different applications.
The E-Commerce firmware also supports cryptographic protocols for secure information exchange such as the Simple Key-Management for Internet Protocol (SKIP) developed by Sun Microsystems Inc.
3.1 Java-Powered Cryptographic iButton
Cryptographic iButton provides secure end-to-end Internet transactions“including granting conditional access to Web pages, signing documents, encrypting sensitive files, securing email and conducting financial transactions safely“even if the client computer, software and communication links are not trustworthy. When PC software and hardware are hacked, information remains safe in the physically secure iButton chip.
Making Life More Convenient and Secure
A physically secure co-processor to a terminal, PC, workstation, or server, the crypto iButton opens up a whole new world of convenience. It connects to the 250 million existing computers with an inexpensive Blue Dot receptor. By simply pressing your Blue Dot with your iButton, you can:
¢ Be granted access privileges to sensitive information on a conditionally accessed Web page using PKI challenge/response authentication.
¢ Sign documents so the recipient can be certain of their origin.
¢ Encrypt and decrypt messages, securing email for the intended eyes only.
¢ Conduct hassle-free monetary transactions“print your own electronic postage stamps or print, write, and sign your own electronic checks.
The Crypto iButton's Extraordinary Security
The National Institute of Standards (NIST) and the Communications Security Establishment (CSE) has validated a version of the crypto iButton for protection of sensitive, unclassified information. FIPS 140-1 validation assures government agencies that the products provide a trusted, physically secure module to properly protect secure information.
As a starting point for the iButton's extraordinary security, the stainless steel case of the device provides clear visual evidence of tampering. The monolithic chip includes up to 134K of SRAM that is specially designed so that it will rapidly erase its contents as a tamper response to an intrusion. Rapid erasing of the SRAM memory is known as zeroization. Any attempts to uncover the private keys within the SRAM are thwarted because attackers have to both penetrate the iButton's barriers and read its contents in less than the time it takes to erase its private keys.
Specific intrusions that result in zeroization include:
¢ Opening the case
¢ Removing the chip's metallurgically bonded substrate barricade
¢ Micro-probing the chip
¢ Subjecting the chip to temperature extremes
In addition, if excessive voltage is encountered, the sole I/O pin is designed to fuse and render the chip inoperable.
As a further security measure, the cryptographic iButton contains a True Time Clock that is a tamper-evident real-time clock. "True Time" differs from real time in that it is set by a reputable agent and its time cannot be reset and is forever increasing. This clock can be used to time stamp transactions. It can also be used to impose expiration dates for inspection intervals, whereby the iButton is required to periodically check in with a host.
The crypto iButton is among the least counterfeitable devices ever made by man. In response to tampering, the crypto iButton would rather erase the key than reveal its secrets. Would-be thieves cannot copy what they do not know“the private key.
4. The Java Card applet model
The Java Ring is in fact a Java smart card, and the ring's virtual machine is based on the Java virtual machine (JVM) that was proposed as the Java Card 2.0 standard. The Java Card architecture has taken client/server architectures to a new place -- one where the "server" is a small piece of software on an extremely small system, and the client is a potentially huge piece of software on a potentially much larger system. The network protocol is encapsulated in packets that are called application program data units, or APDUs for short.
Unlike packets in the TCP/IP world, these APDU packets don't carry any sort of addressing information. Instead, they are implicitly addressed to the computer on the other end of the serial link. However, like their big-brother packets in the TCP/IP world, APDUs do carry a few bytes that are common to all packets. These can be used by the smart card infrastructure to decide when to send the APDUs to the server on the smart card, and when to interpret them directly.
The smart card runtime code gets the first crack at decoding the APDUs as they arrive on the serial interface. Further, there are predefined APDUs that tell the runtime to select an applet, delete applets, load applets, and so on. Thus, errant applets are simply deleted by the developer once it's ascertained that they aren't responding correctly to the APDUs they receive.
The applet sits in a virtual loop, like a network service waiting for packets to arrive on its network interface. The method that handles this loop is named process and is one of four required smart card applet methods. The other three are install, select, and deselect.
The install method must instantiate a new object that represents the applet. Like the main method in a Java application class, the install method is static so that it can be invoked by the smart card JVM before an object exists (it's invoked directly from the class definition).
In the simplest sense, the select and deselect methods tell the applet to either "get ready" or "go to sleep." Actually, the select method has the option of refusing to be selected.
For example, a personal identification number (PIN) or some other authorizing information might need to be passed from the client program to the method (by way of the APDU) before the applet would allow itself to be selected.
The deselect method, on the other hand, doesn't have the ability to deny being deselected -- it provides more of a courtesy to the applet, telling it that it won't be getting any more packets. When a smart card is yanked from the reader before the client is finished, the deselect method isn't even called. The next thing the applet will see will be another invocation of select.
The APDU one could just dump an object or two and have them show up in the ring. But object support isn't part of the package. Instead you get a byte array that you can copy data into, send, receive, and then copy the data back out of.
5. The Java connection
With experience designing the E-Commerce operating system and VM for the Crypto iButton hardware platform, the firmware design team at Dallas Semiconductor could readily appreciate the advantages of a new operating system for the Crypto iButton based on Java. With a Java iButton, a vast number of existing Java programmers could easily learn to write applets that could be compiled with the standard tools available from Sun Microsystems, loaded into the Java iButton, and run on demand to support a wide variety of financial applications. The Java Card 2.0 specification provided the opportunity to implement a useful version of the JVM and runtime environment with the limited resources available to a small processor.
Java Ring
The Crypto iButton also provides an excellent hardware platform for executing Java because it utilizes NVRAM for program and data storage. With 6 kilobytes of existing NVRAM and the potential to expand the NVRAM capacity to as much as 128 kilobytes in the existing iButton form factor, the Crypto iButton can execute Java with a relatively large Java stack situated in NVRAM. This memory acts as conventional high-speed RAM when the processor is executing, and the lithium energy preserves the complete state of the machine while the Java Ring is disconnected from the reader. There is therefore no requirement to deal with persistent objects in a special way -- objects persist or not depending on their scope so the programmer has complete control over object persistence.
As in standard Java, the Java iButton contains a garbage collector that collects any objects that are out of scope and recycles the memory for future use. Applets can be loaded and unloaded from the Java iButton as often as needed. All the applets currently loaded in a Java iButton are effectively executing at zero speed any time the iButton is not in contact with a Blue Dot receptor.
As the Java Card 2.0 specification was proposed, Dallas Semiconductor became a JavaSoft licensee. The agreement called for the development of a Java Card 2.0 implementation and also for the design of "plus portions" that take advantage of the unique capabilities afforded by the Crypto iButtons NVRAM, such as the ability to support a true Java stack and garbage collection.
With the addition of the continuously running lithium-powered time-of-day clock and the high-speed, large-integer modular exponentiation engine, the Java iButton implementation of Java Card 2.0 with plus portions promises an exciting new feature set for advanced Java Card applications.
6. How to keep your money safe?
The Crypto iButton hardware platform offers a unique set of special features expressly designed to prevent private keys and other confidential information from becoming available to hackers. Figure 1 shows a detail of the internal construction of the Crypto iButton.
The silicon die containing the processor, ROM, and NVRAM memory is metallurgically bonded to the barrier substrate through which all electrical contacts are made. This barrier substrate and the triple-layer metal construction techniques employed in the silicon fabrication effectively deny access to the data stored in the NVRAM.
If any attempt is made to penetrate these barriers, the NVRAM data is immediately erased. This construction technique and the use of NVRAM for the storage of private keys and other confidential data provides a much higher degree of data security than that afforded by EEPROM memory. The fact that the communication path between the Crypto iButton and the outside world is limited to a single data line provides additional security against hardware attacks by limiting the range of signals accessible to the hacker.
In addition, the processor itself is driven by an unstabilized ring oscillator operating over a range of 10 to 20 megahertz, so that the clock frequency of the processor is not constant and cannot be determined by external means. This differs from the design of alternative devices in which the processor clock signal is injected by the reader and is therefore exactly determined by the host processor.
External control of the clock provides a valuable tool to hackers, since they can repetitively cycle such a processor to the same point in its execution simply by applying the same number of clock cycles. Control of the clock also affords a means to induce a calculation error and thereby obtain information that can ultimately reveal secret encryption keys. A 32-kilohertz crystal oscillator is used in the Java iButton to operate the time-of-day clock at a constant and well-controlled frequency that is independent of the processor clock.
7. Conclusion
The Java iButton is simply the latest and most complex descendant of a long line of products that have proven themselves to be highly successful in the marketplace. With its stainless steel armor, it offers the most durable packaging for a class of products that likely will suffer heavy use and abuse as personal possessions. The iButton form factor permits attachment to a wide variety of personal accessories that includes rings, watchbands, keyfobs, wallets, bracelets, and necklaces, so the user can select a variation that suits his or her lifestyle.
While the Java iButton can readily support the commerce models that have traditionally been the province of credit cards, its greatest promise appears to lie in its capacity to interact with Internet applications to support strong remote authentication and remotely authorized financial transactions. The use of Java promotes compatibility with these applications by providing a common language for all application programming.
The powerful symbolism of Java being embedded in all shapes and sizes and opening doors to the future now provides the "magic" driving force for the Java Ring. Along with Java Cards, the Java Ring stands poised to open the doors of opportunity for truly personal computing in the information age.
8. Bibliography
http://javaworldjavaworld
http://ibutton.com
http://ibuttoncrypto.html
http://useitpapers/javaring.html
please read http://studentbank.in/report-javaring-se...port--5547
http://studentbank.in/report-javaring-seminars-report
for getting technical report and presentation of java ring
Java Ring is a secure, durable, wearable Java-powered electronic token. It is a tiny wearable computer with 6 kilobytes of RAM. 6 K is enough to hold your secret codes, your credit cards numbers, your driver license, other wallet contents, and even some electronic cash. The ring can also store a few important URLs. Indeed, one of the current Java Ring demos is the ability for us to walk up to any computer in the world that has a Java Ring reader and have our home page loaded simply by touching the ring to the reader .
From a user interface perspective, one can also hope that future rings will be designed by jewelry designers and look less nerdy. Also, it would be possible to gain the same functionality in a watch or a belt buckle. The key issue about a wearable computer is not whether it is a ring or another form factor: The deciding point is that you will always have it with you. Many aspects of computing change once there is no need to go to a special room to get at the computer. It's in the details the Java Ring is an extremely secure Java-powered electronic token with a continuously running, unalterable real-time clock and rugged packaging, suitable for many applications.
The jewel of the Java Ring is the Java iButton -- a one-million transistor, single-chip trusted microcomputer with a powerful Java virtual machine (JVM) housed in a rugged and secure stainless-steel case. Designed to be fully compatible with the Java Card 2.0 standard. The processor features a high-speed 1024-bit modular exponentiator for RSA encryption, large RAM and ROM memory capacity, and an unalterable realtime clock. The packaged module has only a single electrical contact and a ground return, conforming to the specifications of the Dallas Semiconductor 1-Wire bus. Lithium-backed non-volatile SRAM offers high read/write speed and unparalleled tamper resistance through near-instantaneous clearing of all memory when tempering is detected, a feature known as rapid zeroization. Data integrity and clock function are maintained for more than 10 years. The 16-millimeter diameter stainless steel enclosure accommodates the larger chip sizes needed for up to 128 kilobytes of high-speed nonvolatile static RAM. The small and extremely rugged packaging of the module allows it to attach to the accessory of your choice to match individual lifestyles, such as a key fob, wallet, watch, necklace, bracelet, or finger ring.
2. Historical background
In the summer of 1989, Dallas Semiconductor Corp. produced the first stainless-steel-encapsulated memory devices utilizing the Dallas Semiconductor 1-Wire communication protocol. By 1990, this protocol had been refined and employed in a variety of self-contained memory devices. Originally called "touch memory" devices, they were later renamed "iButtons." Packaged like batteries, iButtons have only a single active electrical contact on the top surface, with the stainless steel shell serving as ground.
Data can be read from or written to the memory serially through a simple and inexpensive RS232C serial port adapter, which also supplies the power required to perform the I/O. The iButton memory can be read or written with a momentary contact to the "Blue Dot" receptor provided by the adapter. When not connected to the serial port adapter, memory data is maintained in non-volatile random access memory (NVRAM) by a lifetime lithium energy supply that will maintain the memory content for at least 10 years. Unlike electrically erasable programmable read-only memory (EEPROM), the NVRAM iButton memory can be erased and rewritten as often as necessary without wearing out. It can also be erased or rewritten at the high speeds typical of complementary metal oxide semiconductor (CMOS) memory, without requiring the time-consuming programming of EEPROM.
Since their introduction, iButton memory devices have been deployed in vast quantities as rugged portable data carriers, often in harsh environmental conditions. Among the large-scale uses are as transit fare carriers in Istanbul, Turkey; as maintenance record carriers on the sides of Ryder trucks; and as mailbox identifiers inside the mail compartments of the U.S. Postal Service's outdoor mailboxes. They are worn as earrings by cows in Canada to hold vaccination records, and they are used by agricultural workers in many areas as rugged substitutes for timecards.
Every iButton product is manufactured with a unique 8-byte serial number and carries a guarantee that no two parts will ever have the same number. Among the simplest iButtons are memory devices that can hold files and subdirectories and can be read and written like small floppy disks. In addition to these, there are iButtons with password-protected file areas for security applications, iButtons that count the number of times they have been rewritten for securing financial transactions, iButtons with temperature sensors, iButtons with continuously running date/time clocks, and even iButtons containing powerful microprocessors.
3. The postal security device
For over 10 years, Dallas Semiconductor also has been designing, making, and selling a line of highly secure microprocessors that are used in satellite TV descramblers, automatic teller machines, point-of-sale terminals, and other similar applications requiring cryptographic security and high resistance to attack by hackers. The U.S. Postal Service's (USPS) Information Based Indicia Program Postal Security Device Specification, intended to permit printing of valid U.S. postage on any PC, provided the first opportunity to combine two areas of expertise when a secure microprocessor was designed into an iButton.
The resulting product, named the Crypto iButton, combines high processor performance, high-speed cryptographic primitives, and exceptional protection against physical and cryptographic attack.
For example, the large integer modular exponentiation engine can perform 1024-bit modular exponentiations with a 1024-bit exponent in significantly less than a second. The ability to perform large integer modular exponentiations at high speed is central to RSA encryption, Diffie-Hellman key exchange, Digital Signature Standard (FIPS 186), and many other modern cryptographic operations.
An agreement between Dallas Semiconductor and RSA Data Security Inc. provides a paid-up license for anyone using the Crypto iButton to perform RSA encryption and digital signatures so that no further licensing of the RSA encryption technology is required. High security is afforded by the ability to erase the contents of NVRAM extremely quickly. This feature, rapid zeroization, is a requirement for high security devices that may be subjected to attacks by hackers. As a result of its high security, the Crypto iButton is expected to win the FIPS 140-1 security certification by the National Institute of Standards and Technology (NIST).
A special operating system was designed and stored in the ROM of the Crypto iButton to support cryptography and general-purpose financial transactions -- such as those required by the Postal Service program. While not a Java virtual machine, the E-Commerce firmware designed for this application had several points of similarity with Java, including an object-oriented design and a bytecode interpreter to interpret and execute Dallas Semiconductor's custom-designed E-Commerce Script Language.
A compiler was also written to compile the high-level language representation of the Script Language to a bytecode form that could be interpreted by the E-Commerce VM. Although the E-Commerce firmware was intended primarily for the USPS application, the firmware supports a variety of general electronic commerce models that are suitable for many different applications.
The E-Commerce firmware also supports cryptographic protocols for secure information exchange such as the Simple Key-Management for Internet Protocol (SKIP) developed by Sun Microsystems Inc.
3.1 Java-Powered Cryptographic iButton
Cryptographic iButton provides secure end-to-end Internet transactions“including granting conditional access to Web pages, signing documents, encrypting sensitive files, securing email and conducting financial transactions safely“even if the client computer, software and communication links are not trustworthy. When PC software and hardware are hacked, information remains safe in the physically secure iButton chip.
Making Life More Convenient and Secure
A physically secure co-processor to a terminal, PC, workstation, or server, the crypto iButton opens up a whole new world of convenience. It connects to the 250 million existing computers with an inexpensive Blue Dot receptor. By simply pressing your Blue Dot with your iButton, you can:
¢ Be granted access privileges to sensitive information on a conditionally accessed Web page using PKI challenge/response authentication.
¢ Sign documents so the recipient can be certain of their origin.
¢ Encrypt and decrypt messages, securing email for the intended eyes only.
¢ Conduct hassle-free monetary transactions“print your own electronic postage stamps or print, write, and sign your own electronic checks.
The Crypto iButton's Extraordinary Security
The National Institute of Standards (NIST) and the Communications Security Establishment (CSE) has validated a version of the crypto iButton for protection of sensitive, unclassified information. FIPS 140-1 validation assures government agencies that the products provide a trusted, physically secure module to properly protect secure information.
As a starting point for the iButton's extraordinary security, the stainless steel case of the device provides clear visual evidence of tampering. The monolithic chip includes up to 134K of SRAM that is specially designed so that it will rapidly erase its contents as a tamper response to an intrusion. Rapid erasing of the SRAM memory is known as zeroization. Any attempts to uncover the private keys within the SRAM are thwarted because attackers have to both penetrate the iButton's barriers and read its contents in less than the time it takes to erase its private keys.
Specific intrusions that result in zeroization include:
¢ Opening the case
¢ Removing the chip's metallurgically bonded substrate barricade
¢ Micro-probing the chip
¢ Subjecting the chip to temperature extremes
In addition, if excessive voltage is encountered, the sole I/O pin is designed to fuse and render the chip inoperable.
As a further security measure, the cryptographic iButton contains a True Time Clock that is a tamper-evident real-time clock. "True Time" differs from real time in that it is set by a reputable agent and its time cannot be reset and is forever increasing. This clock can be used to time stamp transactions. It can also be used to impose expiration dates for inspection intervals, whereby the iButton is required to periodically check in with a host.
The crypto iButton is among the least counterfeitable devices ever made by man. In response to tampering, the crypto iButton would rather erase the key than reveal its secrets. Would-be thieves cannot copy what they do not know“the private key.
4. The Java Card applet model
The Java Ring is in fact a Java smart card, and the ring's virtual machine is based on the Java virtual machine (JVM) that was proposed as the Java Card 2.0 standard. The Java Card architecture has taken client/server architectures to a new place -- one where the "server" is a small piece of software on an extremely small system, and the client is a potentially huge piece of software on a potentially much larger system. The network protocol is encapsulated in packets that are called application program data units, or APDUs for short.
Unlike packets in the TCP/IP world, these APDU packets don't carry any sort of addressing information. Instead, they are implicitly addressed to the computer on the other end of the serial link. However, like their big-brother packets in the TCP/IP world, APDUs do carry a few bytes that are common to all packets. These can be used by the smart card infrastructure to decide when to send the APDUs to the server on the smart card, and when to interpret them directly.
The smart card runtime code gets the first crack at decoding the APDUs as they arrive on the serial interface. Further, there are predefined APDUs that tell the runtime to select an applet, delete applets, load applets, and so on. Thus, errant applets are simply deleted by the developer once it's ascertained that they aren't responding correctly to the APDUs they receive.
The applet sits in a virtual loop, like a network service waiting for packets to arrive on its network interface. The method that handles this loop is named process and is one of four required smart card applet methods. The other three are install, select, and deselect.
The install method must instantiate a new object that represents the applet. Like the main method in a Java application class, the install method is static so that it can be invoked by the smart card JVM before an object exists (it's invoked directly from the class definition).
In the simplest sense, the select and deselect methods tell the applet to either "get ready" or "go to sleep." Actually, the select method has the option of refusing to be selected.
For example, a personal identification number (PIN) or some other authorizing information might need to be passed from the client program to the method (by way of the APDU) before the applet would allow itself to be selected.
The deselect method, on the other hand, doesn't have the ability to deny being deselected -- it provides more of a courtesy to the applet, telling it that it won't be getting any more packets. When a smart card is yanked from the reader before the client is finished, the deselect method isn't even called. The next thing the applet will see will be another invocation of select.
The APDU one could just dump an object or two and have them show up in the ring. But object support isn't part of the package. Instead you get a byte array that you can copy data into, send, receive, and then copy the data back out of.
5. The Java connection
With experience designing the E-Commerce operating system and VM for the Crypto iButton hardware platform, the firmware design team at Dallas Semiconductor could readily appreciate the advantages of a new operating system for the Crypto iButton based on Java. With a Java iButton, a vast number of existing Java programmers could easily learn to write applets that could be compiled with the standard tools available from Sun Microsystems, loaded into the Java iButton, and run on demand to support a wide variety of financial applications. The Java Card 2.0 specification provided the opportunity to implement a useful version of the JVM and runtime environment with the limited resources available to a small processor.
Java Ring
The Crypto iButton also provides an excellent hardware platform for executing Java because it utilizes NVRAM for program and data storage. With 6 kilobytes of existing NVRAM and the potential to expand the NVRAM capacity to as much as 128 kilobytes in the existing iButton form factor, the Crypto iButton can execute Java with a relatively large Java stack situated in NVRAM. This memory acts as conventional high-speed RAM when the processor is executing, and the lithium energy preserves the complete state of the machine while the Java Ring is disconnected from the reader. There is therefore no requirement to deal with persistent objects in a special way -- objects persist or not depending on their scope so the programmer has complete control over object persistence.
As in standard Java, the Java iButton contains a garbage collector that collects any objects that are out of scope and recycles the memory for future use. Applets can be loaded and unloaded from the Java iButton as often as needed. All the applets currently loaded in a Java iButton are effectively executing at zero speed any time the iButton is not in contact with a Blue Dot receptor.
As the Java Card 2.0 specification was proposed, Dallas Semiconductor became a JavaSoft licensee. The agreement called for the development of a Java Card 2.0 implementation and also for the design of "plus portions" that take advantage of the unique capabilities afforded by the Crypto iButtons NVRAM, such as the ability to support a true Java stack and garbage collection.
With the addition of the continuously running lithium-powered time-of-day clock and the high-speed, large-integer modular exponentiation engine, the Java iButton implementation of Java Card 2.0 with plus portions promises an exciting new feature set for advanced Java Card applications.
6. How to keep your money safe?
The Crypto iButton hardware platform offers a unique set of special features expressly designed to prevent private keys and other confidential information from becoming available to hackers. Figure 1 shows a detail of the internal construction of the Crypto iButton.
The silicon die containing the processor, ROM, and NVRAM memory is metallurgically bonded to the barrier substrate through which all electrical contacts are made. This barrier substrate and the triple-layer metal construction techniques employed in the silicon fabrication effectively deny access to the data stored in the NVRAM.
If any attempt is made to penetrate these barriers, the NVRAM data is immediately erased. This construction technique and the use of NVRAM for the storage of private keys and other confidential data provides a much higher degree of data security than that afforded by EEPROM memory. The fact that the communication path between the Crypto iButton and the outside world is limited to a single data line provides additional security against hardware attacks by limiting the range of signals accessible to the hacker.
In addition, the processor itself is driven by an unstabilized ring oscillator operating over a range of 10 to 20 megahertz, so that the clock frequency of the processor is not constant and cannot be determined by external means. This differs from the design of alternative devices in which the processor clock signal is injected by the reader and is therefore exactly determined by the host processor.
External control of the clock provides a valuable tool to hackers, since they can repetitively cycle such a processor to the same point in its execution simply by applying the same number of clock cycles. Control of the clock also affords a means to induce a calculation error and thereby obtain information that can ultimately reveal secret encryption keys. A 32-kilohertz crystal oscillator is used in the Java iButton to operate the time-of-day clock at a constant and well-controlled frequency that is independent of the processor clock.
7. Conclusion
The Java iButton is simply the latest and most complex descendant of a long line of products that have proven themselves to be highly successful in the marketplace. With its stainless steel armor, it offers the most durable packaging for a class of products that likely will suffer heavy use and abuse as personal possessions. The iButton form factor permits attachment to a wide variety of personal accessories that includes rings, watchbands, keyfobs, wallets, bracelets, and necklaces, so the user can select a variation that suits his or her lifestyle.
While the Java iButton can readily support the commerce models that have traditionally been the province of credit cards, its greatest promise appears to lie in its capacity to interact with Internet applications to support strong remote authentication and remotely authorized financial transactions. The use of Java promotes compatibility with these applications by providing a common language for all application programming.
The powerful symbolism of Java being embedded in all shapes and sizes and opening doors to the future now provides the "magic" driving force for the Java Ring. Along with Java Cards, the Java Ring stands poised to open the doors of opportunity for truly personal computing in the information age.
8. Bibliography
http://javaworldjavaworld
http://ibutton.com
http://ibuttoncrypto.html
http://useitpapers/javaring.html
please read http://studentbank.in/report-javaring-se...port--5547
http://studentbank.in/report-javaring-seminars-report
for getting technical report and presentation of java ring
