Abstract: Guard tables including absence information are used in a security system to protect a network service from a denial of service attack. A login key corresponding to a login request is hashed and the output of the hash is a bit position in a guard table. The bit value at the bit position in the guard table can be checked to determine if login information corresponding to the key is present. Further processing of the login request can be based on the indicated presence or absence of the information.

Abstract: Methods, systems, and apparatus, including computer program products, for generating or using augmentation queries. In one aspect, statistical model of statistical data is used to support lossless predictive compression. Data instances are identified in statistical data and classified into one of a plurality of data types. Each data type is associated with a corresponding compression process that is used to compress data instances of that type.

Abstract: Systems, methods and apparatus for a distributed security that provides security processing external to a network edge. The system can include many distributed processing nodes and one or more authority nodes that provide security policy data, threat data, and other security data to the processing nodes. The processing nodes detect and stop the distribution of malware, spyware and other undesirable content before such content reaches the destination network and computing systems.

Abstract: Methods, systems, and apparatus, including computer program products, for selective presence notification are provided. In one general aspect, a plurality of presence notification messages are monitored. Each presence notification message may include address information identifying at least one of a recipient or a sender of the presence notification message. Based on the address information a determination is made as to whether a presence notification message is allowable. If it is determined that the presence notification message is allowable, the transmission of the presence notification message is allowed.

Abstract: Systems, methods and apparatus for a distributed security that provides security processing external to a network edge. The system can include many distributed processing nodes and one or more authority nodes that provide security policy data, threat data, and other security data to the processing nodes. The processing nodes detect and stop the distribution of malware, spyware and other undesirable content before such content reaches the destination network and computing systems.

Abstract: Systems, methods and apparatus for a distributed security that provides security processing external to a network edge. The system can include many distributed processing nodes and one or more authority nodes that provide security policy data, threat data, and other security data to the processing nodes. The processing nodes detect and stop the distribution of malware, spyware and other undesirable content before such content reaches the destination network and computing systems.

Abstract: Systems, methods and apparatus for a distributed security that provides security processing external to a network edge. The system can include many distributed processing nodes and one or more authority nodes that provide security policy data, threat data, and other security data to the processing nodes. The processing nodes detect and stop the distribution of malware, spyware and other undesirable content before such content reaches the destination network and computing systems.