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Side-channel Attacks
In computer security, a side-channel attack is a type of security exploit that leverages information inadvertently leaked by a system—such as timing, power consumption, or electromagnetic or acoustic emissions—to gain unauthorized access to sensitive information. These attacks differ from those targeting flaws in the design of cryptography, cryptographic computer protocol, protocols or algorithm, algorithms. (Cryptanalysis may identify vulnerabilities relevant to both types of attacks). Some side-channel attacks require technical knowledge of the internal operation of the system, others such as differential power analysis are effective as Black-box testing, black-box attacks. The rise of Web 2.0 applications and software-as-a-service has also significantly raised the possibility of side-channel attacks on the web, even when transmissions between a web browser and server are encrypted (e.g. through HTTPS or WiFi encryption), according to researchers from Microsoft Research and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Attack
Power may refer to: Common meanings * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power, a type of energy * Power (social and political), the ability to influence people or events Mathematics, science and technology Computing * IBM POWER (software), an IBM operating system enhancement package * IBM POWER architecture, a RISC instruction set architecture * Power ISA, a RISC instruction set architecture derived from PowerPC * IBM Power microprocessors, made by IBM, which implement those RISC architectures * Power.org, a predecessor to the OpenPOWER Foundation Mathematics * Exponentiation, "''x'' to the power of ''y''" * Power function * Power of a point * Statistical power Physics * Magnification, the factor by which an optical system enlarges an image * Optical power, the degree to which a lens converges or diverges light Social sciences and politics * Economic power, encompassing several concepts that economists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cache (computing)
In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A cache hit occurs when the requested data can be found in a cache, while a cache miss occurs when it cannot. Cache hits are served by reading data from the cache, which is faster than recomputing a result or reading from a slower data store; thus, the more requests that can be served from the cache, the faster the system performs. To be cost-effective, caches must be relatively small. Nevertheless, caches are effective in many areas of computing because typical Application software, computer applications access data with a high degree of locality of reference. Such access patterns exhibit temporal locality, where data is requested that has been recently requested, and spatial locality, where data is requested that is stored near dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic Key
A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ..., can Encryption, encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key's security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange. Scope The key is what is used to encrypt data from plaintext to ciphertext. There are different methods for utilizing keys and encryption. Symmetric cryptography Symmetric cryptography refers to the pra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptosystem
In cryptography, a cryptosystem is a suite of cryptographic algorithms needed to implement a particular security service, such as confidentiality (encryption). Typically, a cryptosystem consists of three algorithms: one for key generation, one for encryption, and one for decryption. The term ''cipher'' (sometimes ''cypher'') is often used to refer to a pair of algorithms, one for encryption and one for decryption. Therefore, the term ''cryptosystem'' is most often used when the key generation algorithm is important. For this reason, the term ''cryptosystem'' is commonly used to refer to public key techniques; however both "cipher" and "cryptosystem" are used for symmetric key techniques. Formal definition Mathematically, a cryptosystem or encryption scheme can be defined as a tuple (\mathcal,\mathcal,\mathcal,\mathcal,\mathcal) with the following properties. # \mathcal is a set called the "plaintext space". Its elements are called plaintexts. # \mathcal is a set called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitelist
A whitelist or allowlist is a list or register of entities that are being provided a particular privilege, service, mobility, access or recognition. Entities on the list will be accepted, approved and/or recognized. Whitelisting is the reverse of blacklisting, the practice of identifying entities that are denied, unrecognized, or ostracized. Email whitelists Spam filters often include the ability to "whitelist" certain sender IP addresses, email addresses or domain names to protect their email from being rejected or sent to a junk mail folder. These can be manually maintained by the user or system administrator - but can also refer to externally maintained whitelist services. Non-commercial whitelists Non-commercial whitelists are operated by various non-profit organizations, ISPs, and others interested in blocking spam. Rather than paying fees, the sender must pass a series of tests; for example, their email server must not be an open relay and have a static IP address. The o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Row Hammer
Rowhammer (also written as row hammer or RowHammer) is a computer security exploit that takes advantage of an unintended and undesirable side effect in dynamic random-access memory (DRAM) in which memory cell (computing), memory cells interact electrically between themselves by leaking their charges, possibly changing the contents of nearby memory rows that were not memory address, addressed in the original memory access. This circumvention of the isolation between DRAM memory cells results from the high cell density in modern DRAM, and can be triggered by specially crafted memory access patterns that rapidly activate the same memory rows numerous times. The Rowhammer effect has been used in some privilege escalation computer security exploit (computer security), exploits, and network-based attacks are also theoretically possible. Different hardware-based techniques exist to prevent the Rowhammer effect from occurring, including required support in some central processing unit, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Boot Attack
In computer security, a cold boot attack (or to a lesser extent, a platform reset attack) is a type of side channel attack in which an attacker with physical access to a computer performs a memory dump of a computer's random-access memory (RAM) by performing a hard reset of the target machine. Typically, cold boot attacks are used for retrieving encryption keys from a running operating system for malicious or criminal investigative reasons. The attack relies on the data remanence property of DRAM and SRAM to retrieve memory contents that remain readable in the seconds to minutes following a power switch-off. An attacker with physical access to a running computer typically executes a cold boot attack by cold-booting the machine and booting a lightweight operating system from a removable disk to dump the contents of pre-boot physical memory to a file. An attacker is then free to analyze the data dumped from memory to find sensitive data, such as the keys, using various forms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Remanence
Data remanence is the residual representation of digital data that remains even after attempts have been made to remove or erase the data. This residue may result from data being left intact by a nominal file deletion operation, by reformatting of storage media that does not remove data previously written to the media, or through physical properties of the storage media that allow previously written data to be recovered. Data remanence may make inadvertent disclosure of sensitive information possible should the storage media be released into an uncontrolled environment (''e.g.'', thrown in the bin (trash) or lost). Various techniques have been developed to counter data remanence. These techniques are classified as clearing, purging/sanitizing, or destruction. Specific methods include overwriting, degaussing, encryption, and media destruction. Effective application of countermeasures can be complicated by several factors, including media that are inaccessible, media that c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Fault Analysis
Differential fault analysis (DFA) is a type of active side-channel attack in the field of cryptography, specifically cryptanalysis. The principle is to induce ''faults''—unexpected environmental conditions—into cryptographic operations to reveal their internal states. Principles Taking a smartcard containing an embedded processor as an example, some unexpected environmental conditions it could experience include being subjected to high temperature, receiving unsupported supply voltage or current, being excessively overclocked, experiencing strong electric or magnetic fields, or even receiving ionizing radiation to influence the operation of the processor. When stressed like this, the processor may begin to output incorrect results due to physical data corruption, which may help a cryptanalyst Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acoustic Cryptanalysis
Acoustic cryptanalysis is a type of side-channel attack that exploits sounds emitted by computers or other devices. Most of the modern acoustic cryptanalysis focuses on the sounds produced by computer keyboards and internal computer components, but historically it has also been applied to impact printers, and electromechanics, electromechanical deciphering machines. History Victor Marchetti and John D. Marks eventually negotiated the declassification of CIA acoustic intercepts of the sounds of cleartext printing from encryption machines. Technically this method of attack dates to the time of Fast Fourier transform, FFT hardware being cheap enough to perform the task; in this case the late 1960s to mid-1970s. However, using other more primitive means such acoustical attacks were made in the mid-1950s. In his book ''Spycatcher'', former MI5 operative Peter Wright (MI5 officer), Peter Wright discusses use of an acoustic attack against Egyptian Boris Hagelin, Hagelin cipher machine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van Eck Phreaking
Van Eck phreaking, also known as Van Eck radiation, is a form of network eavesdropping in which special equipment is used for a side-channel attack on the electromagnetic emissions of electronic devices. While electromagnetic emissions are present in keyboards, printers, and other electronic devices, the most notable use of Van Eck phreaking is in reproducing the contents of a cathode-ray tube (CRT) display at a distance. Information that drives a CRT video display takes the form of electrical signals in the RF range. The electric signal which drives the electron beam is amplified to up to around one hundred volts from TTL circuitry. The signal leaks out from displays and may be captured by an antenna, and once synchronization pulses are recreated and mixed in, an ordinary analog television receiver can display the result. These emissions are correlated to the video image being displayed, so, in theory, they can be used to recover the displayed image. While the phenomenon ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tempest (codename)
TEMPEST is a codename, not an acronym under the U.S. National Security Agency specification and a NATO certification referring to spying on information systems through leaking emanations, including unintentional radio or electrical signals, sounds, and vibrations. TEMPEST covers both methods to spy upon others and how to shield equipment against such spying. The protection efforts are also known as emission security (EMSEC), which is a subset of communications security (COMSEC). The reception methods fall under the umbrella of radiofrequency MASINT. The NSA methods for spying on computer emissions are classified, but some of the protection standards have been released by either the NSA or the Department of Defense. Protecting equipment from spying is done with distance, shielding, filtering, and masking. The TEMPEST standards mandate elements such as equipment distance from walls, amount of shielding in buildings and equipment, and distance separating wires carrying classified v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
