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GEOM
GEOM is the main storage framework for the FreeBSD operating system. It is available in FreeBSD 5.0 and later releases, and provides a standardized way to access storage layers. GEOM is modular and allows for ''geom modules'' to connect to the framework. For example, the geom_mirror module provides RAID1 or mirroring functionality to the system. A number of modules are provided as part of FreeBSD and others have been developed independently and are distributed via (e.g.) GitHub. GEOM was developed for the FreeBSD Project by Poul-Henning Kamp and NAI Labs, the Security Research Division of Network Associates, Inc. under DARPA/ SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research program. The name symbolizes its impact on disk geometry. Stacked design Because of geom's modular design, modules can be 'stacked' together to form a chain of geom layers. For example, on top of the geom_mirror module an encryption module can be added, such as geom_eli to pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FreeBSD
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular open-source BSD operating system, accounting for more than three-quarters of all installed and permissively licensed BSD systems. FreeBSD has similarities with Linux, with two major differences in scope and licensing: FreeBSD maintains a complete system, i.e. the project delivers a kernel, device drivers, userland utilities, and documentation, as opposed to Linux only delivering a kernel and drivers, and relying on third-parties for system software; FreeBSD source code is generally released under a permissive BSD license, as opposed to the copyleft GPL used by Linux. The FreeBSD project includes a security team overseeing all software shipped in the base distribution. A wide range of additional third-party applications may be installe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GBDE
GBDE, standing for GEOM Based Disk Encryption, is a block device-layer disk encryption system written for FreeBSD, initially introduced in version 5.0. It is based on the GEOM disk framework. GBDE was designed and implemented by Poul-Henning Kamp and Network Associates Inc. (now known as McAfee). Design decisions Unlike most disk encryption software, GBDE does not attempt to defeat watermarking attacks through the use of disk encryption-specific modes of operation (see disk encryption theory), but instead generates a random key each time a sector is written. Unlike some alternatives, such as CBC with sector-specific initialization vectors, this approach does not reveal any information to the attacker even if they have access to snapshots of the disk image from different points in time, since encryption keys are never re-used. The one time sector key is encrypted using a pseudorandom key. This pseudorandom key is derived from the sector number and a static 2048-bit master key with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poul-Henning Kamp
Poul-Henning Kamp (; born 1966) is a Danish computer software developer known for work on various projects including FreeBSD and Varnish. He currently resides in Slagelse, Denmark. Involvement in the FreeBSD project Poul-Henning Kamp has been committing to the FreeBSD project for most of its duration. He is responsible for the widely used MD5crypt implementation of the MD5 password hash algorithm, a vast quantity of systems code including the FreeBSD GEOM storage layer, GBDE cryptographic storage transform, part of the UFS2 file system implementation, FreeBSD Jails, malloc library, and the FreeBSD and NTP timecounters code. Varnish cache He is the lead architect and developer for the open source Varnish cache project, an HTTP accelerator. Dispute with D-Link In 2006, Kamp had a dispute with electronics manufacturer D-Link in which he claimed they were committing NTP vandalism by embedding the IP address of his NTP servers in their routers. The dispute was resolved in Apr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geli (software)
geli is a block device-layer disk encryption system written for FreeBSD, introduced in version 6.0. It uses the GEOM disk framework. It was designed and implemented by Paweł Jakub Dawidek. Design details geli was initially written to protect data on a user's computer in situations of physical theft of hardware, disallowing the thief access to the protected data. This has changed over time with the introduction of optional data authentication/integrity verification. geli allows the key to consist of several information components (a user entered passphrase, random bits from a file, etc.), permits multiple keys (a user key and a company key, for example) and can attach a provider with a random, one-time key. The user passphrase is strengthened with PKCS#5. Differences from GBDE The geli utility is different from gbde in that it offers different features and uses a different scheme for doing cryptographic work. It supports the crypto framework within FreeBSD, allowing hardware c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix File System
The Unix file system (UFS) is a family of file systems supported by many Unix and Unix-like operating systems. It is a distant descendant of the original filesystem used by Version 7 Unix. Design A UFS volume is composed of the following parts: * A few blocks at the beginning of the partition reserved for boot blocks (which must be initialized separately from the filesystem) * A superblock, containing a magic number identifying this as a UFS filesystem, and some other vital numbers describing this filesystem's geometry and statistics and behavioral tuning parameters * A collection of cylinder groups. Each cylinder group has the following components: ** A backup copy of the superblock ** A cylinder group header, with statistics, free lists, etc., about this cylinder group, similar to those in the superblock ** A number of inodes, each containing file attributes ** A number of data blocks Inodes are numbered sequentially, starting at 0. Inode 0 is reserved for unallocated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geom Raid5
geom_raid5 is a storage module created for the FreeBSD operating system. It facilitates RAID5 functionality without the need of a hardware RAID controller. geom_raid5 allows storage of large amounts of data to be protected against disk failure, while providing good throughput performance. Like other FreeBSD storage modules, geom_raid5 utilizes the GEOM framework. It is built as a kernel loadable module (KLD) which allows it to run inside the FreeBSD kernel. The module can be compiled on FreeBSD release 5 and newer releases. geom_raid5 is also incorporated into FreeNAS, an operating system dedicated to Network Attached Storage. Its author, Arne Woerner, has released the software under the BSD license, making geom_raid5 OSI-compliant open source software. Comparing to other Software RAID5 solutions geom_raid5 distinguishes itself by providing both advanced features and high performance. While the theoretical maximum write speed is , the latest version is able to achieve about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHA512
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression function itself built using the Davies–Meyer structure from a specialized block cipher. SHA-2 includes significant changes from its predecessor, SHA-1. The SHA-2 family consists of six hash functions with digests (hash values) that are 224, 256, 384 or 512 bits: SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256. SHA-256 and SHA-512 are novel hash functions computed with eight 32-bit and 64-bit words, respectively. They use different shift amounts and additive constants, but their structures are otherwise virtually identical, differing only in the number of rounds. SHA-224 and SHA-384 are truncated versions of SHA-256 and SHA-512 respectively, computed with different initial values. SHA-512/224 and SHA-512/256 are also trunca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHA384
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression function itself built using the Davies–Meyer structure from a specialized block cipher. SHA-2 includes significant changes from its predecessor, SHA-1. The SHA-2 family consists of six hash functions with digests (hash values) that are 224, 256, 384 or 512 bits: SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256. SHA-256 and SHA-512 are novel hash functions computed with eight 32-bit and 64-bit words, respectively. They use different shift amounts and additive constants, but their structures are otherwise virtually identical, differing only in the number of rounds. SHA-224 and SHA-384 are truncated versions of SHA-256 and SHA-512 respectively, computed with different initial values. SHA-512/224 and SHA-512/256 are also trunca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JBOD
The most widespread standard for configuring multiple hard disk drives is RAID (Redundant Array of Inexpensive/Independent Disks), which comes in a number of standard configurations and non-standard configurations. Non-RAID drive architectures also exist, and are referred to by acronyms with tongue-in-cheek similarity to RAID: * JBOD (derived from "just a bunch of disks"): described multiple hard disk drives operated as individual independent hard disk drives. * SPAN or BIG: A method of combining the free space on multiple hard disk drives from "JBoD" to create a spanned volume. Such a concatenation is sometimes also called BIG/SPAN. A SPAN or BIG is generally a spanned volume only, as it often contains mismatched types and sizes of hard disk drives. * MAID (derived from "massive array of idle drives"): an architecture using hundreds to thousands of hard disk drives for providing nearline storage of data, primarily designed for "Write Once, Read Occasionally" (WORO) applications, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHA1
In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecimal digits. It was designed by the United States National Security Agency, and is a U.S. Federal Information Processing Standard. Since 2005, SHA-1 has not been considered secure against well-funded opponents; as of 2010 many organizations have recommended its replacement. NIST formally deprecated use of SHA-1 in 2011 and disallowed its use for digital signatures in 2013, and declared that it should be phased out by 2030. , chosen-prefix attacks against SHA-1 are practical. As such, it is recommended to remove SHA-1 from products as soon as possible and instead use SHA-2 or SHA-3. Replacing SHA-1 is urgent where it is used for digital signatures. All major web browser vendors ceased acceptance of SHA-1 SSL certificates in 2017. In February ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camellia (cipher)
In cryptography, Camellia is a symmetric key block cipher with a block size of 128 bits and key sizes of 128, 192 and 256 bits. It was jointly developed by Mitsubishi Electric and NTT of Japan. The cipher has been approved for use by the ISO/IEC, the European Union's NESSIE project and the Japanese CRYPTREC project. The cipher has security levels and processing abilities comparable to the Advanced Encryption Standard. The cipher was designed to be suitable for both software and hardware implementations, from low-cost smart cards to high-speed network systems. It is part of the Transport Layer Security (TLS) cryptographic protocol designed to provide communications security over a computer network such as the Internet. The cipher was named for the flower ''Camellia japonica'', which is known for being long-lived as well as because the cipher was developed in Japan. Design Camellia is a Feistel cipher with either 18 rounds (when using 128-bit keys) or 24 rounds (when using 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triple DES
In cryptography, Triple DES (3DES or TDES), officially the Triple Data Encryption Algorithm (TDEA or Triple DEA), is a symmetric-key block cipher, which applies the DES cipher algorithm three times to each data block. The Data Encryption Standard's (DES) 56-bit key is no longer considered adequate in the face of modern cryptanalytic techniques and supercomputing power. A CVE released in 2016, CVE-2016-2183' disclosed a major security vulnerability in DES and 3DES encryption algorithms. This CVE, combined with the inadequate key size of DES and 3DES, NIST has deprecated DES and 3DES for ''new'' applications in 2017, and for ''all'' applications by the end of 2023. It has been replaced with the more secure, more robust AES. While the government and industry standards abbreviate the algorithm's name as TDES (Triple DES) and TDEA (Triple Data Encryption Algorithm), RFC 1851 referred to it as 3DES from the time it first promulgated the idea, and this namesake has since come into wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
