摘要:
The invention provides methods, apparatus and systems for detecting distributed denial of service (DDoS) attacks within the Internet by sampling packets at a point or points in Internet backbone connections to determine a packet metric parameter. The packet metric parameter which might comprise the volume of packets received is analysed over selected time intervals with respect to specified geographical locations in which the hosts transmitting the packets are located. The expected behaviour can be employed to identify traffic distortions revealing a DDoS attack. In a complementary aspect, the invention provides a method of authenticating packets at routers in order to elevate the QoS of authenticated packets. This method can be used to block or filter packets and can be used in conjunction with the DDoS attack detection system to defend against DDoS attacks within the Internet in a distributed manner.
摘要:
A method and apparatus for identifying an unwanted short message service (SMS) message from SMS messages received by a cellular mobile communication system, which comprises at least a history database (HB) for storing a set (H) of the messages received by the cellular mobile communication system. The method includes the steps of: measuring a difference in an information content between a SMS message (m) received by the cellular mobile communication system and the set (H) of messages stored in the history database (HB), and marking the SMS message (m) as being an unwanted SMS message if the difference that is measured is less than or equal to a predefined threshold value.
摘要:
A data processing entity that includes a mass memory with a plurality of memory locations for storing memory blocks. Each of a plurality of software images includes a plurality of memory blocks with corresponding image addresses within the software image. The memory blocks of software images stored in boot locations of a current software image are relocated. The boot blocks of the current software image are stored into the corresponding boot locations. The data processing entity is booted from the boot blocks of the current software image in the corresponding boot locations, thereby loading the access function. Each request to access a selected memory block of the current software image is served by the access function, with the access function accessing the selected memory block in the associated memory location provided by the control structure.
摘要:
Auditable data distribution from a server to clients is achieved as follows. The server delivers chunks of a data file, and identifiers of the chunks, to the clients. For each chunk of the data file received by the clients, a digest is generated by the client that received the chunk, using at least a part of the chunk and further data of the client that received the chunk. The further data is known to the server. The client that received this chunk sends the digest to the server, which receives the digest. The server determines an identity of the clink that received the chunk in question, by comparing the digest to the chunks that the server has sent and to the further data known to the server. The server stores the identity of the client that received the chunk.
摘要:
A method for determining a representation (y) of a signal (s) comprise selecting a predetermined number (m) of row vectors (v1, . . . , vm) from a predetermined measurement matrix (M). The predetermined measurement matrix (M) is predetermined dependent on a product of a predetermined Hadamard matrix or generalized Hadamard matrix (H) and a predetermined representation matrix(B). The predetermined representation matrix (B) represents a predetermined basis for the signal(s). The method further comprises determining a respective inner product of the signal (s) and each of the predetermined number (m) of selected row vectors (v1, . . . , vm) resulting in a predetermined number (m) of measurements (y1, . . . , ym) forming the representation (y) of the signal (s).
摘要:
A method for storing a file on a data storage device. The method includes: storing the file in one of a first and a second file system; calculating a hash value; and storing the hash value on a storage device if it is stored in the second file system. A data processing system includes a first file system and a second file system wherein the data processing system calculates and stores a hash value when the file is stored in the second file system. A method for reading a file from a file system including: receiving a read command; reading a first hash value from a storage device; reading the file from the storage device; calculating a second hash value; returning the file when the first hash value equals the second hash value and returning an error when it does not equal the second hash value.
摘要:
An index server support for file sharing applications is disclosed. A way of retrieving an index server includes sending a request for investigating a hierarchical structure of index servers in a network to a known index server, intercepting the investigation request by the first index server that becomes aware of the investigation request, notifying an originator of the investigation request of the intercepting index server identity, dropping the intercepted request is dropped by the intercepting index server. The originator of the investigation request then registers the intercepting index server as addressee for future file querying requests.
摘要:
An index server support for file sharing applications is disclosed. A way of retrieving an index server includes sending a request for investigating a hierarchical structure of index servers in a network to a known index server, intercepting the investigation request by the first index server that becomes aware of the investigation request, notifying an originator of the investigation request of the intercepting index server identity, dropping the intercepted request is dropped by the intercepting index server. The originator of the investigation request then registers the intercepting index server as addressee for future file querying requests.
摘要:
A data processing entity that includes a mass memory with a plurality of memory locations for storing memory blocks. Each of a plurality of software images includes a plurality of memory blocks with corresponding image addresses within the software image. The memory blocks of software images stored in boot locations of a current software image are relocated. The boot blocks of the current software image are stored into the corresponding boot locations. The data processing entity is booted from the boot blocks of the current software image in the corresponding boot locations, thereby loading the access function. Each request to access a selected memory block of the current software image is served by the access function, with the access function accessing the selected memory block in the associated memory location provided by the control structure.
摘要:
A method, system and computer program product for managing multiple software images in a data processing entity. At least part of the memory blocks of each of the software images is stored into a corresponding image portion of a mass memory. A current software image stored in a current image is selected. The memory blocks stored in boot locations of the current software image are relocated to a relocation portion of the mass memory. The boot blocks of the current software image are copied into the corresponding boot location. The data processing entity is booted from the boot blocks of the current software image in the corresponding boot locations and each request to access a selected memory block of the current software image by the access function is served.