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File Fixity
File fixity is a digital preservation In library science, library and archival science, digital preservation is a formal process to ensure that digital information of continuing value remains accessible and usable in the long term. It involves planning, resource allocation, and appli ... term referring to the property of a digital file being fixed, or unchanged. Fixity checking is the process of verifying that a digital object has not been altered or corrupted. During transfer, a repository may run a fixity check to ensure a transmitted file has not been altered en route. Within the repository, fixity checking is used to ensure that digital files have not been affected by data rot, or other digital preservation dangers. By itself, fixity checking does not ensure the preservation of a digital file. Instead, it allows a repository to identify which corrupted files to replace with a clean copy from the producer or from a backup. In practice, a fixity check is most often accomplished ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Preservation
In library science, library and archival science, digital preservation is a formal process to ensure that digital information of continuing value remains accessible and usable in the long term. It involves planning, resource allocation, and application of Preservation (library and archive), preservation methods and Technology, technologies,Day, Michael. "The long-term preservation of Web content". Web archiving (Berlin: Springer, 2006), pp. 177-199. . and combines policies, strategies and actions to ensure access to digital reformatting, reformatted and "born-digital" content, regardless of the challenges of media failure and technological change. The goal of digital preservation is the accurate rendering of authenticated content over time.Evans, Mark; Carter, Laura. (December 2008). The Challenges of Digital Preservation. Presentation at the Library of Parliament, Ottawa. The Association for Library Collections and Technical Services Preservation and Reformatting Section of the A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Rot
Data degradation is the gradual corruption of computer data due to an accumulation of non-critical failures in a data storage device. It is also referred to as data decay, data rot or bit rot. This results in a decline in data quality over time, even when the data is not being utilized. The concept of data degradation involves progressively minimizing data in interconnected processes, where data is used for multiple purposes at different levels of detail. At specific points in the process chain, data is irreversibly reduced to a level that remains sufficient for the successful completion of the following steps Manifestations Primary storages Data degradation in dynamic random-access memory (DRAM) can occur when the electric charge of a bit in DRAM disperses, possibly altering program code or stored data. DRAM may be altered by cosmic rays or other high-energy particles. Such data degradation is known as a soft error. ECC memory can be used to mitigate this type of data degrad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Checksum
A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify data integrity but are not relied upon to verify data authenticity. The procedure which generates this checksum is called a checksum function or checksum algorithm. Depending on its design goals, a good checksum algorithm usually outputs a significantly different value, even for small changes made to the input. This is especially true of cryptographic hash functions, which may be used to detect many data corruption errors and verify overall data integrity; if the computed checksum for the current data input matches the stored value of a previously computed checksum, there is a very high probability the data has not been accidentally altered or corrupted. Checksum functions are related to hash functions, fingerprints, randomization functio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic Hash Function
A cryptographic hash function (CHF) is a hash algorithm (a map (mathematics), map of an arbitrary binary string to a binary string with a fixed size of n bits) that has special properties desirable for a cryptography, cryptographic application: * the probability of a particular n-bit output result (hash value) for a random input string ("message") is 2^ (as for any good hash), so the hash value can be used as a representative of the message; * finding an input string that matches a given hash value (a ''pre-image'') is infeasible, ''assuming all input strings are equally likely.'' The ''resistance'' to such search is quantified as security strength: a cryptographic hash with n bits of hash value is expected to have a ''preimage resistance'' strength of n bits, unless the space of possible input values is significantly smaller than 2^ (a practical example can be found in ); * a ''second preimage'' resistance strength, with the same expectations, refers to a similar problem of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implementation Strategies (PREMIS)
Implementation is the realization of an application, execution of a plan, idea, model, design, specification, standard, algorithm, policy, or the administration or management of a process or objective. Industry-specific definitions Information technology In the information technology industry, implementation refers to the post-sales process of guiding a client from purchase to use of the software or hardware that was purchased. This includes requirements analysis, scope analysis, customizations, systems integrations, user policies, user training and delivery. These steps are often overseen by a project manager using project management methodologies. Software Implementations involve several professionals that are relatively new to the knowledge based economy such as business analysts, software implementation specialists, solutions architects, and project managers. To implement a system successfully, many inter-related tasks need to be carried out in an appropriate sequence. U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Government Publishing Office
The United States Government Publishing Office (USGPO or GPO), formerly the United States Government Printing Office, is an agency of the legislative branch of the United States federal government. The office produces and distributes information products and services for all three branches of the Federal Government, including U.S. passports for the Department of State as well as the official publications of the Supreme Court, the Congress, the Executive Office of the President, executive departments, and independent agencies. An act of Congress changed the office's name to its current form in 2014. History Establishment of the Government Printing Office The Government Printing Office was created by congressional joint resolution () on June 23, 1860. It began operations March 4, 1861, with 350 employees and reached a peak employment of 8,500 in 1972. The agency began transformation to computer technology in the 1980s; along with the gradual replacement of paper with el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
