Abstract: Systems and methods for constructing Reed-Solomon encoding matrices are provided that are simpler and more regular than existing techniques, and which allow for the coding to be applied to more data disks than previous techniques. More particularly, systems and methods for simplifying the construction of Reed-Solomon based erasure codes, or coding matrices, over GF(2^n) in connection with circumstances wherein the number of errors to be corrected is less than or equal to three are provided.

Abstract: Nodal pattern configuration is described, including generating successive values at a source node, processing the successive values using a plurality of intermediate nodes, sending the processed values from a node in the plurality of intermediate nodes to a destination node, and configuring the plurality of intermediate nodes such that each node of the plurality of intermediate nodes, concurrently performs at least two actions. Also, nodal pattern configuration includes generating a series of data blocks at a source node, processing data blocks from the series of data blocks using a plurality of intermediate nodes in data communication with the source node, each node of the plurality of intermediate nodes being configured to concurrently perform at least two operations, and sending processed data blocks from the plurality of intermediate nodes to a destination node, the destination node being in data communication with the plurality of intermediate nodes.

Abstract: Documents that are near-duplicates may be determined using techniques such as min-hashing. Randomness that is used in these techniques may be based on sequences of bits. The sequences of bits may be generated from a string of bits, with the sequences determined by parsing the string at each occurrence of a particular value, such as the value “1”.

Abstract: An implementation of a disk drive with improved efficiency where a read head supported by a first positioning component is provided and a write head supported by a second positioning component is also provided. By positioning the write head behind the read head at a predetermined angle, the disk drive can execute a “read-before-write” or “read-modify-by-XOR-write” operation by before the platter has rotated a full revolution.

Abstract: Techniques are provided that identify near-duplicate items in large collections of items. A list of (value, frequency) pairs is received, and a sample (value, instance) is returned. The value is chosen from the values of the first list, and the instance is a value less than frequency, in such a way that the probability of selecting the same sample from two lists is equal to the similarity of the two lists.

Abstract: When a user successfully logs into an account, the user is provided with a first-class login token, which entitles the user to one or more unsuccessful login attempts without experiencing delays the user would otherwise experience. If attempts with a second-class login token or an expired first-class login token is impermissible, a subsequent login attempt is subject to delays the user would otherwise not experience. The delays minimize the effectiveness of dictionary attacks. Additionally, if the user attempts to login without a login token or an invalid login token, the login attempt is impermissible and the user is provided with a second-class login token for use in a delayed, subsequent login attempt.

Abstract: The present invention extends to methods, systems, and computer program products for scalable differential compression for network data. Network data exchanged between Wide Area Network (“WAN”) acceleration devices is cached at physical recordable-type computer-readable media having (potentially significantly) larger storage capacities than available system memory. The cached network data is indexed through features taken from a subset of the cached data (e.g., per segment) to reduce overhead associated with searching for cached network data to use for subsequent compression. When a feature match is detected between received and cached network data, the cached network data can be loaded from the physical recordable-type computer-readable media into system memory to facilitate data compression between Wide Area Network (“WAN”) acceleration devices more efficiently.

Abstract: A resource may be abused if its users incur little or no cost. For example, e-mail abuse is rampant because sending an e-mail has negligible cost for the sender. Such abuse may be discouraged by introducing an artificial cost in the form of a moderately expensive computation. Thus, the sender of an e-mail might be required to pay by computing for a few seconds before the e-mail is accepted. Unfortunately, because of sharp disparities across computer systems, this approach may be ineffective against malicious users with high-end systems, prohibitively slow for legitimate users with low-end systems, or both. Starting from this observation, we identify moderately hard, memory bound functions that most recent computer systems will evaluate at about the same speed, and we explain how to use them for protecting against abuses.

Abstract: Systems and methods for constructing Reed-Solomon encoding matrices are provided that are simpler and more regular than existing techniques, and which allow for the coding to be applied to more data disks than previous techniques. More particularly, systems and methods for simplifying the construction of Reed-Solomon based erasure codes, or coding matrices, over GF(2{circumflex over ( )}n) in connection with circumstances wherein the number of errors to be corrected is less than or equal to three are provided.

Abstract: A resource may be abused if its users incur little or no cost. For example, e-mail abuse is rampant because sending an e-mail has negligible cost for the sender. Such abuse may be discouraged by introducing an artificial cost in the form of a moderately expensive computation. Thus, the sender of an e-mail might be required to pay by computing for a few seconds before the e-mail is accepted. Unfortunately, because of sharp disparities across computer systems, this approach may be ineffective against malicious users with high-end systems, prohibitively slow for legitimate users with low-end systems, or both. Starting from this observation, we identify moderately hard, memory bound functions that most recent computer systems will evaluate at about the same speed, and we explain how to use them for protecting against abuses.

Abstract: When a user successfully logs into an account, the user is provided with a first-class login token, which entitles the user to one or more unsuccessful login attempts without experiencing delays the user would otherwise experience. If attempts with a second-class login token or an expired first-class login token is impermissible, a subsequent login attempt is subject to delays the user would otherwise not experience. The delays minimize the effectiveness of dictionary attacks. Additionally, if the user attempts to login without a login token or an invalid login token, the login attempt is impermissible and the user is provided with a second-class login token for use in a delayed, subsequent login attempt.

Abstract: Provided is a computerized method for monitoring the content of documents. A set of documents is stored in memories of server computers. The server computers can be connected to each other by a network such as the Internet. Entries are generated in a search engine for each document of the set. The search engine is also connected to the Internet. The entries are in the form of a full word index of the set of documents. The search engine also maintains a first abstract for each document that is indexed. The abstract is highly dependent on the content of each document. For example, the abstract is in the form of a sketch or a feature vector. Periodically a query is submitted to the search engine. The query locates a result set of documents that satisfy the query. A second abstract is generated for each document member of the result set. The first and second abstracts are compared to identify documents that have changed between the time the set of documents were indexed and the time the result set is generated.