Bulldozer Core (AMD)

Bulldozer is the codename AMD has given to one of the next-generation CPU cores after the K10 microarchitecture for the company's M-SPACE design methodology, with the core specifically aimed at 10 watt to 100 watt TDP computing products. Bulldozer is a completely new design developed from the ground up. AMD claims dramatic performance-per-watt improvements in HPC applications with Bulldozer cores. Products implementing the Bulldozer core are planned for release in 2011.

According to AMD, Bulldozer-based CPUs will be based on advanced 32nm SOI process technology and utilize a new approach to multithreaded computer performance that, according to press notes, "balances dedicated and shared compute resources to provide a highly compact, high core count design that is easily replicated on a chip for performance scaling." In other words, by eliminating some of the redundancies that naturally creep into multicore designs, AMD hopes to take better advantage of its hardware capabilities, while utilizing less power.

The Bulldozer cores will support most of the instruction sets currently implemented in Intel processors (including SSE4.1, SSE4.2, AES, CLMUL), future Instruction sets announced by Intel (AVX), as well as future instruction sets proposed by AMD (XOP and FMA4).

As of November 2009, Bulldozer-based implementations built on 32nm SOI with HKMG are scheduled to arrive in 2011 for both servers and desktops, as the 16-core Opteron processor codenamed Interlagos and as the 4- or 8-core desktop processor codenamed Zambezi.

Bulldozer is the next-generation micro-architecture and processor design developed from the ground up by AMD. Bulldozer will be the first major redesign of AMD’s processor architecture since 2003, when the firm launched its Athlon 64/Opteron (K8) processors. Bulldozer will feature two 128-bit FMA-capable FPUs which can be combined into one 256-bit FPU. This design is accompanied with two integer cores each with 4 pipelines (the fetch/decode stage is shared). Bulldozer will also introduce shared L2 cache in the new architecture. AMD calls this design a "Bulldozer module". A 16-core processor design would feature eight of these modules, but the operating system will see each module as two physical cores.

The module is similar to an SMT core, but enhanced with a dedicated integer core and scheduler for each thread. Because the shared floating point core is significantly enhanced, performance could get beyond that of two equivalent Bobcat cores while one of the running threads is integer-only.

Bulldozer Design Breakdown

* Two tightly coupled, "conventional" x86 out-of-order processing engines which AMD internally named module
(Single-Module ==> Dual-Core, Dual-Module ==> Quad-Core, Quad-Module ==> Octa-Core etc...)
* Between 8MB to 16MB of L3 cache shared among all Modules on the same silicon die
* DDR3-1866 and Higher Memory Level Parallelism
* Dual channel DDR3 integrated memory controler (support for PC3-12800 (DDR3-1600))
* Cluster Multi-threading (CMT) Technology
* Bulldozer module consists of the following:
o 128kB L2 cache inside each module (shared between module cores)
o 4kB L1 data cache per core and 2-way 16kB L1 instruction cache per module L1 cache, Fruehe for THW
o Two dedicated integer cores
- each consist of 2 ALU and 2 AGU which are capable for total of 4 independent arithmetic or memory operations per clock per core
- duplicating integer schedulers and execution pipelines offers dedicated hardware to each of two threads which significantly increase performance in multithreaded integer applications
- second integer core increases Bulldozer module die by around 12%, which at chip level adds about 5% of total die space[9]
o Two symmetrical 128-bit FMAC (fused multiply-add (FMA) capability) Floating Point Pipelines per module that can be unified into one large 256-bit wide unit if one of integer cores dispatch AVX instruction and two symmetrical x87/MMX/3DNow! capable FPPs for backward compatibility with SSE2 non-optimized software
* 32nm SOI process with implemented first generation GF's High-K Metal Gate (HKMG)
* Support for AMD's only SSE5 128-bit instructions
- incl. three smaller supplemental extensions CVT16, XOP and FMA4 instruction set, which are now part of SSE5 specification (since May 2009 revision)
* Support for Intel's Advanced Vector Extensions (AVX) (Supports 256-Bit FP Operations via AVX)SSE4.1, SSE4.2, AES, CLMUL), future Instruction sets announced by Intel (AVX), as well as future instruction sets proposed by AMD (XOP and FMA4
* Hyper Transport Technology rev.3.1 (3.20 GHz, 6.4 GT/s, 51.6 GB/s, 16-bit uplink/16-bit downlink) [first implemented into HY-D1 revision "Magny-Cours" on the socket G34 Opteron platform in March 2010 and "Lisbon" on the socket C32 Opteron platform in June 2010]
* Socket AM3+ (AM3r2)
- 938pin(?), DDR3 support
- will retain only backwards compatiblity with previous Socket AM3/AM2 processors ("new AM3+ socket for consumer versions of Bulldozer CPUs. AM2 and AM3 processors will work in the AM3+ socket, but Bulldozer chips will not work in non-AM3+ motherboards")
* Min-Max Power Usage - 10-100 watts
* Bulldozer Module sharing levels Bulldozer module

Deniable Encryption

In cryptography and steganography, deniable encryption is encryption that allows its users to convincingly deny the fact that the data is encrypted or, assuming that the data is obviously encrypted, its users can convincingly deny that they are able to decrypt it. Such convincing denials may or may not be genuine, e.g., although suspicions might exist that the data is encrypted, it may be impossible to prove it without the cooperation of the users. In any case, even if the data is encrypted then the users genuinely may not have the ability to decrypt it. Deniable encryption serves to undermine an attacker's confidence either that data is encrypted, or that the person in possession of it can decrypt it and provide the associated plaintext.

Normally ciphertexts decrypt to a single plaintext and hence once decrypted, the encryption user cannot claim that he encrypted a different message. Deniable encryption allows its users to decrypt the ciphertext to produce a different (innocuous but plausible) plaintext and insist that it is what they encrypted. The holder of the ciphertext will not have the means to differentiate between the true plaintext, and the bogus-claim plaintext.

Deniable encryption allows an encrypted message to be decrypted to different sensible plaintexts, depending on the key used, or otherwise makes it impossible to prove the existence of the real message without the proper encryption key. This allows the sender to have plausible deniability if compelled to give up his or her encryption key. The notion of "deniable encryption" was introduced by Julian Assange & Ralf Weinmann in the Rubberhose filesystem and explored in detail in a paper by Ran Canetti, Cynthia Dwork, Moni Naor, and Rafail Ostrovsky in 1996.

Modern forms of deniable encryption

Modern deniable encryption techniques exploit the pseudorandom permutation properties of existing block ciphers, making it cryptographically infeasible to prove that the ciphertext is not random padding data generated by a cryptographically secure pseudorandom number generator. This is used in combination with some decoy data that the user would plausibly want to keep confidential that will be revealed to the attacker, claiming that this is all there is. This form of deniable encryption is sometimes referred to as "steganographic encryption".

One example of deniable encryption is a cryptographic filesystem that employs a concept of abstract "layers", where each layer would be decrypted with a different encryption key. Additionally, special "chaff layers" are filled with random data in order to have plausible deniability of the existence of real layers and their encryption keys. The user will store decoy files on one or more layers while denying the existence of others, claiming that the rest of space is taken up by chaff layers. Physically, these types of filesystems are typically stored in a single directory consisting of equal-length files with filenames that are either randomized (in case they belong to chaff layers), or cryptographic hashes of strings identifying the blocks. The timestamps of these files are always randomized. Examples of this approach include Rubberhose filesystem and PhoneBookFS.

Another approach utilized by some conventional disk encryption software suites is creating a second encrypted volume within a container volume. The container volume is first formatted by filling it with encrypted random data and then initializing a filesystem on it. The user then fills some of the filesystem with legitimate, but plausible-looking decoy files that the user would seem to have an incentive to hide. Next, a new encrypted volume (the hidden volume) is allocated within the free space of the container filesystem which will be used for data the user actually wants to hide. Since an adversary cannot differentiate between encrypted data and the random data used to initialize the outer volume, this inner volume is now undetectable. Concerns have, however, been raised for the level of plausible deniability in hiding information this way – the contents of the "outer" container filesystem (in particular the access or modification timestamps on the data stored) could raise suspicions as a result of being frozen in its initial state to prevent the user from corrupting the hidden volume. This problem can be eliminated by instructing the system not to protect the hidden volume, although this could result in lost data. FreeOTFE and BestCrypt can have many hidden volumes in a container; TrueCrypt is limited to one hidden volume.

Needless to say, insecure block ciphers or pseudorandom number generators can make it possible to compromise the deniability of such filesystems. To escape the assumption that the used pseudorandom number generation is cryptographically secure, it has been advised to instead fill the encrypted space with pseudorandom data which has itself been encrypted, thus being protected by a separate encryption key since encrypted data is impossible to differentiate from encrypted data In addition to that, the flawed use of block cipher modes of operation can also compromise the cipher algorithm due to watermarking attacks.

Singularity

Singularity is a video game developed by Raven Software published by Activision and released for Microsoft Windows, Xbox 360, and PlayStation 3, Singularity is Raven Software's second title based on Epic Games' Unreal Engine 3. The title was announced at Activision's E3 2008 press conference.

The game takes place on a mysterious island known as "Katorga-12" where Russian experiments involving "E99" took place during the height of the Cold War era. Sometime during 1955, a terrible catastrophe involving experiments attempting to form a "Singularity" occurred on the island, causing the island's very existence to be covered up by the Russian government. The player controls Nate Renko, a Black Ops soldier who is sent to investigate bizarre radiation emissions coming from the island. The operation goes poorly when team crashes during transport and the operation is scrapped. After regaining consciousness, Renko discovers that the island is constantly shifting between the time periods of 1955 and 2010. Renko acidentally shifts the timeline by saving a scientist who died in 1955. Renko finds the TMD (Time Manipulation Device), a device created by Dr. Victor Barisov. Barisov, the scientist who was in charge of the Katorga-12 experiments, reveals that a man named Nikolai Demichev, also a scientist on Katorga-12, used E99 technology to conquer the world. During the quest to stop Demichev, the player deals with hostile Russian forces in both time periods, and the mutated flora, fauna and former residents of the island, some of which have developed extreme power of their own.

In response to the United States' development and deployment of the atomic bomb, Joseph Stalin makes nuclear research the top scientific priority of the USSR. On a small island near Kamchatka, scientists discover an isotope of E99 that has strange properties. A research base named Katorga-12 is established on the island. E99-related research continued on the island until late 1955, when the island was destroyed by an accident. The Soviet government then erased any information about Katorga-12 and suppressed public knowledge of the accident.

In 2010, a sudden electromagnetic surge from Katorga-12 damages an American spy satellite. A military reconnaissance team is sent to investigate the uninhabited island, but a second surge causes their helicopter to crash. Captain Nathaniel Renko, a member of the reconnaissance team, enters the abandoned scientific complex on the island, where he phases between 1955 and 2010.

Renko is first transported back to 1955 during a major fire at the facility, where he saves one Nikolai Demichev. As this happens, an unidentified man yells, "Renko, stop! Don't let Demichev live!", before being killed by a ceiling collapse. Dr. Demichev would have otherwise died in the fire; by rescuing him, Renko altered history. Renko is abruptly returned to the year 2010, where he discovers that the island has changed. He encounters strange and violent creatures, and regroups with Devlin, a second survivor of the helicopter crash. Both soldiers are captured by Russian soldiers under the command of Demichev. Devlin demands asylum at the American embassy, at which point he is executed by Demichev.

Renko is saved by an organization called Mir-12. Mir-12 is a secretive resistance organization that bases its existence off of a journal recovered from the accident on Katorga-12. The journal declares that Nathaniel Renko will be able to stop Demichev using the "TMD", or "Time Manipulation Device". This device was apparently created by Dr. Viktor Barisov, who died in a laboratory accident, leaving Demichev to command the research base and eventually rule the world. Kathryn tells Renko to find the TMD and use it to go back in time and save Barisov. Renko succeeds and returns to 2010, where Barisov is now alive and well.

Barisov and Renko plan to fix history by going back in time and destroying the island's Singularity tower with an E-99 bomb. Renko recovers an E99 bomb from a sunken ship (the Pearl), but Kathryn dies in the process.

Renko and Barisov then fight their way into the Singularity Tower, which lies at the heart of Katorga-12. When they reach the tower's reactor, Renko travels back in time and uses the E99 bomb to destroy the reactor; he returns to 2010 moments before the tower is destroyed. It is implied that this explosion triggered the destruction of the Singularity and mutated the island's population.

Upon returning to 2010, Renko finds that nothing has changed. He sees Demichev holding Barisov at gunpoint. Demichev reveals that he rebuilt the facility after the bomb was detonated (presumably at another location). Renko shoots and non-fatally wounds Demichev, freeing Barisov. Barisov realizes that Demichev's rescue is what altered the timeline, and tells Renko that the only way to fix the timeline is for Renko to go back in time and stop himself from rescuing Demichev. Demichev reveals that Renko already tried that; he was the unidentified man that Renko saw in the fire. The three realize that the only way for Renko to stop Demichev's rescue is to kill his past self. Demichev offers Renko unlimited power in exchange for the TMD. The player is left with a choice resulting in three endings, based on whether Renko shoots Demichev, Barisov, or both men.

If the player shoots Barisov, he joins forces with Demichev and the team succeed in taking over most of the world, with Renko training the Katorga-12 mutants as soldiers and using them as first wave attackers in all of his battles. But with his control of the TMD, Demichev feels Renko is even more powerful than he is and takes precautionary measures against him by starting a weapons research program in the former United States. This settles the world into another Cold War with Renko on one side and Demichev on the other, although Renko is most likely to win, seeing he has almost complete control over the East and his power is slowly consuming the West.

If the player shoots both Demichev and Barisov, Renko leaves Katorga-12 and allows the world to fall into chaos. The public believes his very existence to be a myth as he disappears with the TMD in his possession. The Singularity explodes some years later and destroys the eastern coast of Russia and the Western coast of Alaska. Katorga-12 mutants escape onto mainland Russia and wreak havoc. A new leader rises in the former United States and is reported to be very aggressive and tyrannical as he leads the entire world with an iron fist. The in-game cutscenes and narration heavily imply the leader to be Renko himself.

If the player chooses to kill Demichev, or if he shoots neither man, then Barisov urges Renko to go back in time and stop himself from rescuing Demichev by killing his past self. The player then assumes the position of the man who shouted at Renko in the fire, only instead of being crushed by debris, he shoots the past Renko. Shooting the past version of Renko sends the narrative back to Devlin and Renko's arrival at Katorga-12. The game's intro credits are shown written in Russian, the helicopters bear the hammer and sickle on the side, and Devlin, armed with a Russian weapon, comments that monitoring Katorga-12 is a waste of time. The helicopter moves past the statue seen in the intro credits, but it has changed into a massive monument to Barisov wearing the TMD. Renko seems to have retained his memories from the rest of the game, as he checks his left hand when he sees the monument. Renko and Devlin's mission is called off by their dispatcher -- Red Fleet instead of Titan One -- and Devlin refers to Renko as "comrade". It is implied that Barisov recovered the TMD from the fire and used it to unite the world under Soviet rule.

A post-credit scene shows a wounded Kathryn emerging in 1955 from the Pearl's wreckage and hiding in an office. Bleeding heavily, she writes "Renko" in the Mir-12 journal.

Single Point of Failure

A single point of failure (SPOF) is a part of a system which, if it fails, will stop the entire system from working. They are undesirable in any system whose goal is high availability, be it a network, software application or other industrial system.



The assessment of a potentially single location of failure identifies the critical components of a complex system that would provoke a total systems failure in case of malfunction. Highly reliable systems may not rely on any such individual component.

Deep Crack

In cryptography, the EFF DES cracker (nicknamed "Deep Crack") is a machine built by the Electronic Frontier Foundation (EFF) in 1998 to perform a brute force search of DES cipher's key space — that is, to decrypt an encrypted message by trying every possible key. The aim in doing this was to prove that DES's key is not long enough to be secure.

DES uses a 56-bit key, meaning that there are 2^56 possible keys under which a message can be encrypted. This is exactly 72,057,594,037,927,936, or approximately 72 quadrillion, possible keys. When DES was approved as a federal standard in 1976, a machine fast enough to test that many keys in a reasonable time would have cost an unreasonable amount of money to build.

Deep Crack was designed by Cryptography Research, Inc., Advanced Wireless Technologies and the EFF. The principal designer was Paul Kocher, president of Cryptography Research. Advanced Wireless Technologies built 1856 custom ASIC DES chips (called Deep Crack or AWT-4500), housed on 29 circuit boards of 64 chips each. The boards were then fitted in six cabinets and mounted in a Sun-4/470 chasis. The search was coordinated by a single PC which assigned ranges of keys to the chips. The entire machine was capable of testing over 90 billion keys per second. It would take about 9 days to test every possible key at that rate. On average, the correct key would be found in half that time.



In 2006, another custom hardware attack machine was designed based on FPGAs. COPACOBANA (COst-optimized PArallel COdeBreaker) shows a similar performance as Deep Crack at considerably lower cost. This advantage is mainly due to progress in IC technology.

Since DES was a federal standard, the US government encouraged the use of DES for all non-classified data. RSA Security wished to demonstrate that DES's key length was not enough to ensure security, so they set up the DES Challenges in 1997, offering a monetary prize. The first DES Challenge was solved in 96 days by the DESCHALL Project led by Rocke Verser in Loveland, Colorado. RSA Security set up DES Challenge II-1, which was solved by distributed.net in 41 days in January and February 1998.





In 1998, the EFF built Deep Crack for less than $250,000. In response to DES Challenge II-2, on July 17, 1998, Deep Crack decrypted a DES-encrypted message after only 56 hours of work, winning $10,000. This was the final blow to DES, against which there were already some published cryptanalytic attacks. The brute force attack showed that cracking DES was actually a very practical proposition. For well-endowed governments or corporations, building a machine like Deep Crack would be no problem.

Six months later, in response to RSA Security's DES Challenge III, and in collaboration with distributed.net, the EFF used Deep Crack to decrypt another DES-encrypted message, winning another $10,000. This time, the operation took less than a day — 22 hours and 15 minutes. The decryption was completed on January 19, 1999. In October of that year, DES was reaffirmed as a federal standard, but this time the standard recommended Triple DES (also referred to as 3DES or TDES).

The small key-space of DES, and relatively high computational costs of triple DES resulted in its replacement by AES as a Federal standard, effective May 26, 2002.

Rubik's Cube

The Rubik's Cube is a 3-D mechanical puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik. Originally called the "Magic Cube", the puzzle was licensed by Rubik to be sold by Ideal Toys in 1980 and won the German Game of the Year special award for Best Puzzle that year. As of January 2009, 350 million cubes have sold worldwide making it the world's top-selling puzzle game. It is widely considered to be the world's best-selling toy.

In a classic Rubik's Cube, each of the six faces is covered by nine stickers, among six solid colours (traditionally white, red, blue, orange, green, and yellow). A pivot mechanism enables each face to turn independently, thus mixing up the colours. For the puzzle to be solved, each face must be a solid colour. Similar puzzles have now been produced with various numbers of stickers, not all of them by Rubik. The original 3×3×3 version celebrates its thirtieth anniversary in 2010.

There are many algorithms to solve scrambled Rubik's Cubes. The minimum number of face turns needed to solve any instance of the Rubik's cube is 20. This number is also known as the diameter of the Cayley graph of the Rubik's Cube group. An algorithm that solves a cube in the minimum number of moves is known as God's algorithm.

There are two common ways to measure the length of a solution. The first is to count the number of quarter turns. The second is to count the number of face turns. A move like F2 (a half turn of the front face) would be counted as 2 moves in the quarter turn metric and as only 1 turn in the face metric.

In 2006, Silviu Radu further improved his methods to prove that every position can be solved in at most 27 face turns or 35 quarter turns. Daniel Kunkle and Gene Cooperman in 2007 used a supercomputer to show that all unsolved cubes can be solved in no more than 26 moves (in face-turn metric). Instead of attempting to solve each of the billions of variations explicitly, the computer was programmed to bring the cube to one of 15,000 states, each of which could be solved within a few extra moves. All were proved solvable in 29 moves, with most solvable in 26. Those that could not initially be solved in 26 moves were then solved explicitly, and shown that they too could be solved in 26 moves.

Tomas Rokicki reported in 2008 computational proof that all unsolved cubes could be solved in 25 moves or fewer. This was later reduced to 23 moves. In August 2008 Rokicki announced that he had a proof for 22 moves. In 2009, Tomas Rokicki proved that 29 moves in quarter turn metric is enough to solve any scrambled cube. Finally, in 2010, an international Group around Morley Davidson gave the final proof that all cube positions could be solved with a maximum of 20 face turns.

Metallic Hydrogen

Metallic hydrogen is a state of hydrogen which results when it is sufficiently compressed and undergoes a phase transition; it is an example of degenerate matter. Solid metallic hydrogen is predicted to consist of a crystal lattice of hydrogen nuclei (namely, protons), with a spacing which is significantly smaller than the Bohr radius. Indeed, the spacing is more comparable with the de Broglie wavelength of the electron. The electrons are unbound and behave like the conduction electrons in a metal. In liquid metallic hydrogen, protons do not have lattice ordering; rather, it is a liquid system of protons and electrons.

Liquid metallic hydrogen

Helium-4 is a liquid at normal pressure and temperatures near absolute zero, a consequence of its high zero-point energy (ZPE). The ZPE of protons in a dense state is also high, and a decline in the ordering energy (relative to the ZPE) is expected at high pressures. Arguments have been advanced by Neil Ashcroft and others that there is a melting point maximum in compressed hydrogen, but also that there may be a range of densities (at pressures around 400 GPa) where hydrogen may be a liquid metal, even at low temperatures.

Astrophysics

Metallic hydrogen is thought to be present in large amounts in the gravitationally compressed interiors of Jupiter, Saturn, and some of the newly discovered extrasolar planets. Because previous predictions of the nature of those interiors had taken for granted metallization at a higher pressure than the one at which we now know it to happen, those predictions must now be adjusted. The new data indicate much more metallic hydrogen must exist inside Jupiter than previously thought, that it comes closer to the surface, and that therefore, Jupiter's tremendous magnetic field, the strongest of any planet in the solar system is, in turn, produced closer to the surface.