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34-504: The C7 delivers a number of improvements to the older VIA C3 cores but is nearly identical to the latest VIA C3 Nehemiah core. The C7 was officially launched in May 2005, although according to market reports, full volume production was not in place at that date. In May 2006 Intel's cross-licensing agreement with VIA expired and was not renewed, which was the reason for the forced termination of C3 shipments on March 31, 2006, as VIA lost rights to

68-523: A comparator . If the voltage is above threshold, the comparator output is 1, otherwise 0. The random bit value is latched using a flip-flop. Sources of noise vary and include: The drawbacks of using noise sources for an RNG design are: The idea of chaos-based noise stems from the use of a complex system that is hard to characterize by observing its behavior over time. For example, lasers can be put into (undesirable in other applications) chaos mode with chaotically fluctuating power, with power detected using

102-462: A photodiode and sampled by a comparator. The design can be quite small, as all photonics elements can be integrated on-chip. Stipčević & Koç characterize this technique as "most objectionable", mostly due to the fact that chaotic behavior is usually controlled by a differential equation and no new randomness is introduced, thus there is a possibility of the chaos-based TRNG producing a limited subset of possible output strings. The TRNGs based on

136-407: A TRNG (when compared with pseudo random number generators) provide no meaningful benefits. TRNGs have additional drawbacks for data science and statistical applications: impossibility to re-run a series of numbers unless they are stored, reliance on an analog physical entity can obscure the failure of the source. The TRNGs therefore are primarily used in the applications where their unpredictability and

170-515: A fast-rotating 10-sector disk that was illuminated by periodic bursts of light. The sampling was done by a human who wrote the number under the light beam onto a pad. The device was utilized to produce a 100,000-digit random number table (at the time such tables were used for statistical experiments, like PRNG nowadays). On 29 April 1947, the RAND Corporation began generating random digits with an "electronic roulette wheel", consisting of

204-559: A free-running oscillator (FRO) typically utilize one or more ring oscillators (ROs), outputs of which are sampled using yet another oscillator. Since inverters forming the RO can be thought of as amplifiers with a very large gain, an FRO output exhibits very fast oscillations in phase in frequency domains. The FRO-based TRNGs are very popular due to their use of the standard digital logic despite issues with randomness proofs and chip-to-chip variability. Quantum random number generation technology

238-450: A free-running oscillator-based TRNG can be attacked using a frequency injection . There are mathematical techniques for estimating the entropy of a sequence of symbols. None are so reliable that their estimates can be fully relied upon; there are always assumptions which may be very difficult to confirm. These are useful for determining if there is enough entropy in a seed pool, for example, but they cannot, in general, distinguish between

272-515: A large and carefully prepared table had never before been available. It has been a useful source for simulations, modeling, and for deriving the arbitrary constants in cryptographic algorithms to demonstrate that the constants had not been selected maliciously (" nothing up my sleeve numbers "). Since the early 1950s, research into TRNGs has been highly active, with thousands of research works published and about 2000 patents granted by 2017. A lot of different TRNG designs were proposed over time with

306-402: A large variety of noise sources and digitization techniques ("harvesting"). However, practical considerations (size, power, cost, performance, robustness) dictate the following desirable traits: Stipčević & Koç in 2014 classified the physical phenomena used to implement TRNG into four groups: Noise-based RNGs generally follow the same outline: the source of a noise generator is fed into

340-465: A random bit) dates at least to the times of ancient Rome . The first documented use of a physical random number generator for scientific purposes was by Francis Galton (1890). He devised a way to sample a probability distribution using a common gambling dice. In addition to the top digit, Galton also looked at the face of a dice closest to him, thus creating 6*4 = 24 outcomes (about 4.6 bits of randomness). Kendall and Babington-Smith (1938) used

374-446: A random frequency pulse source of about 100,000 pulses per second gated once per second with a constant frequency pulse and fed into a five-bit binary counter. Douglas Aircraft built the equipment, implementing Cecil Hasting's suggestion (RAND P-113) for a noise source (most likely the well known behavior of the 6D4 miniature gas thyratron tube, when placed in a magnetic field ). Twenty of the 32 possible counter values were mapped onto

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408-594: A sense that they can only operate in a fully controlled, trusted environment. The failure of a TRNG can be quite complex and subtle, necessitating validation of not just the results (the output bit stream), but of the unpredictability of the entropy source. Hardware random number generators should be constantly monitored for proper operation to protect against the entropy source degradation due to natural causes and deliberate attacks. FIPS Pub 140-2 and NIST Special Publication 800-90B define tests which can be used for this. The minimal set of real-time tests mandated by

442-423: Is expected to output near-perfect random numbers (" full entropy "). A physical process usually does not have this property, and a practical TRNG typically includes a few blocks: Hardware random number generators generally produce only a limited number of random bits per second. In order to increase the available output data rate, they are often used to generate the " seed " for a faster PRNG. DRBG also helps with

476-668: Is sold in five main versions: The Esther (C5J) is the next evolution step of the Nehemiah+ (C5P) core of the VIA C3 line-up. New Features of this core include: VIA C3 The VIA C3 is a family of x86 central processing units for personal computers designed by Centaur Technology and sold by VIA Technologies . The different CPU cores are built following the design methodology of Centaur Technology . In addition to x86 instructions, VIA C3 CPUs contain an undocumented Alternate Instruction Set allowing lower-level access to

510-661: Is thermal, not quantum. ) The "Nehemiah+" (C5P) (stepping 8) revision brought a few more advancements, including a high-performance AES encryption engine along with a notably small ball grid array chip package the size of a US 1 cent coin . At the time VIA also boosted the FSB to 200 MHz and introduced new chipsets such as the CN400 to support it. The new 200 MHz FSB chips are only available in BGA packages, as they are not compatible with existing Socket 370 motherboards. When this architecture

544-505: Is well established with 8 commercial quantum random number generator ( QRNG ) products offered before 2017. Herrero-Collantes & Garcia-Escartin list the following stochastic processes as "quantum": To reduce costs and increase robustness of quantum random number generators, online services have been implemented. A plurality of quantum random number generators designs are inherently untestable and thus can be manipulated by adversaries. Mannalath et al. call these designs "trusted" in

578-620: The P4 Prescott ) encountered severe thermal management issues, although the later Intel Core generation of chips were substantially cooler. VIA's embedded platform products have reportedly (2005) been adopted in Nissan's car series, the Lafesta , Murano , and Presage . These and other high volume industrial applications are starting to generate big profits for VIA as the small form factor and low power advantages close embedded deals. On

612-556: The Socket 370 . A 1 GHz C7 processor with 128kB of cache memory is used in VIA's own PX10000G motherboard which is based on the proprietary Pico-ITX form factor. The chip is cooled by a large heatsink that covers most of the board and a small 40mm fan. In early April 2008 the schoolroom-use oriented, ultra-portable HP 2133 Mini-Note PC family debuted with an entirely VIA-based, 1.0, 1.2 and 1.6 GHz C7-M processor portfolio, where

646-465: The photoelectric effect , involving a beam splitter , other quantum phenomena, and even the nuclear decay (due to practical considerations the latter, as well as the atmospheric noise, is not viable). While "classical" (non-quantum) phenomena are not truly random, an unpredictable physical system is usually acceptable as a source of randomness, so the qualifiers "true" and "physical" are used interchangeably. A hardware random number generator

680-506: The 10 decimal digits and the other 12 counter values were discarded. The results of a long run from the RAND machine, filtered and tested, were converted into a table, which originally existed only as a deck of punched cards , but was later published in 1955 as a book, 50 rows of 50 digits on each page ( A Million Random Digits with 100,000 Normal Deviates ). The RAND table was a significant breakthrough in delivering random numbers because such

714-451: The C3 fit those traits rather well. Centaur Technology concentrated on adding features attractive to the embedded marketplace. An example built into the first "Nehemiah" (C5XL) core were the twin hardware random number generators . (These generators are falsely stated to be “quantum-based” in VIA's marketing literature. Detailed analysis of the generator makes it clear that the source of randomness

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748-553: The CPU and in some cases privilege escalation . VIA Cyrix III was renamed VIA C3 with the switch to the advanced "Samuel 2" (C5B) core. The addition of an on-die L2 cache improved performance somewhat. As it was not built upon Cyrix technology at all, the new name was just a logical step. To improve power consumption and reduce manufacturing costs, Samuel 2 was produced with 150 nm process technology. The VIA C3 processor continued an emphasis on minimizing power consumption with

782-470: The basis of the IDT Centaur acquisition, VIA appears to have come into possession of at least three patents, which cover key aspects of processor technology used by Intel. On the basis of the negotiating leverage these patents offered, in 2003 VIA arrived at an agreement with Intel that allowed for a ten-year patent cross license, enabling VIA to continue to design and manufacture x86 compatible CPUs. VIA

816-519: The certification bodies is not large; for example, NIST in SP 800-90B requires just two continuous health tests : Just as with other components of a cryptography system, a cryptographic random number generator should be designed to resist certain attacks . Defending against these attacks is difficult without a hardware entropy source. The physical processes in HRNG introduce new attack surfaces. For example,

850-495: The cmov instruction, making it a 686-class processor. The Linux kernel refers to this core as the C3-2. It also removes 3DNow! instructions in favour of implementing SSE . However, it was still based upon the aging Socket 370 , running the single data rate front-side bus at just 133 MHz. Because the embedded system marketplace prefers low-power, low-cost CPU designs, VIA began targeting this segment more aggressively because

884-415: The cryptographic applications: A typical way to fulfill these requirements is to use a TRNG to seed a cryptographically secure pseudorandom number generator . Physical devices were used to generate random numbers for thousands of years, primarily for gambling . Dice in particular have been known for more than 5000 years (found on locations in modern Iraq and Iran), and flipping a coin (thus producing

918-462: The design. Uniquely, the retail C3 CPU shipped inside a decorative tin . The "Nehemiah" (C5XL) was a major core revision. At the time, VIA's marketing efforts did not fully reflect the changes that had taken place. The company addressed numerous design shortcomings of the older cores, including the half-speed FPU . The number of pipeline stages was increased from 12 to 16, to allow for continued increases in clock speed. Additionally, it implemented

952-579: The device always has access to a physical entropy source ), unlike the pseudorandom number generator (PRNG, a.k.a. "deterministic random bit generator", DRBG) that utilizes a deterministic algorithm and non-physical nondeterministic random bit generators that do not include hardware dedicated to generation of entropy. Many natural phenomena generate low-level, statistically random " noise " signals, including thermal and shot noise, jitter and metastability of electronic circuits, Brownian motion , and atmospheric noise . Researchers also used

986-418: The impossibility to re-run the sequence of numbers are crucial to the success of the implementation: in cryptography and gambling machines. The major use for hardware random number generators is in the field of data encryption , for example to create random cryptographic keys and nonces needed to encrypt and sign data. In addition to randomness, there are at least two additional requirements imposed by

1020-407: The lowest speed model is optimized for running an SSD -based 4GB Linux distribution with a sub $ 500 price tag, while the middle tier carries Windows XP and the top model comes with Windows Vista Business, factory default. HP chose the single-core VIA C7-M CPU in order to meet the already fixed $ 499 starting price, even though Intel's competing Atom processor line debuted on 2 April 2008. The C7

1054-407: The next die shrink to a mixed 130/150 nm process. "Ezra" (C5C) and "Ezra-T" (C5N) were only new revisions of the "Samuel 2" core with some minor modifications to the bus protocol of "Ezra-T" to match compatibility with Intel's Pentium III "Tualatin" cores. VIA enjoyed the lowest power usage in the x86 CPU market for several years. Performance, however, fell behind due to the lack of improvements to

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1088-515: The noise source "anonymization" (whitening out the noise source identifying characteristics) and entropy extraction . With a proper DRBG algorithm selected ( cryptographically secure pseudorandom number generator , CSPRNG), the combination can satisfy the requirements of Federal Information Processing Standards and Common Criteria standards. Hardware random number generators can be used in any application that needs randomness. However, in many scientific applications additional cost and complexity of

1122-466: Was also granted a three-year period of grace in which it could continue to use Intel socket infrastructure. Hardware random number generator In computing , a hardware random number generator ( HRNG ), true random number generator ( TRNG ), non-deterministic random bit generator ( NRBG ), or physical random number generator is a device that generates random numbers from a physical process capable of producing entropy (in other words,

1156-472: Was marketed it was often referred to as the "VIA C5". While slower than x86 CPUs being sold by AMD and Intel , both in absolute terms and on a clock-for-clock basis, VIA's chips were much smaller, cheaper to manufacture, and lower power. This made them highly attractive in the embedded marketplace. This also enabled VIA to continue to scale the frequencies of their chips with each manufacturing process die shrink, while competitive products from Intel (such as

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