34 results about "Nondeterministic finite automaton" patented technology

A hardware accelerator personality compiler, by distinguishing the marks corresponding to each executable function, logo, variable, syntax, grammatical rules, special symbols, etc. Formal notation provides the specification of a set of expected executable functions, automatically generating error-free state tables. The tokens can be recursive (eg infinite), in which case the tokens are transformed into deterministic finite automata or non-deterministic finite automata. The non-deterministic finite automaton is transformed into a finite automaton and then into state transitions for creating a state table which can then be stored, or preferably loaded into a finite state machine of a hardware parser accelerator , to define its personality.

Deterministic Finite Automatons (DFAs) and Nondeterministic Finite Automatons (NFAs) are two typical automatons used in the Network Intrusion Detection System (NIDS). Although they both perform regular expression matching, they have quite different performance and memory usage properties. DFAs provide fast and deterministic matching performance but suffer from the well-known state explosion problem. NFAs are compact, but their matching performance is unpredictable and with no worst case guarantee. A new automaton representation of regular expressions, called Tunable Finite Automaton (TFA), is described. TFAs resolve the DFAs' state explosion problem and the NFAs' unpredictable performance problem. Different from a DFA, which has only one active state, a TFA allows multiple concurrent active states. Thus, the total number of states required by the TFA to track the matching status is much smaller than that required by the DFA. Different from an NFA, a TFA guarantees that the number of concurrent active states is bounded by a bound factor b that can be tuned during the construction of the TFA according to the needs of the application for speed and storage. A TFA can achieve significant reductions in the number of states and memory space.

States included in a deterministic finite automaton are classified into states having the same input symbols associated with outgoing transitions and the same finality, and a calculates an intersection set between each of the state sets and a set of transition destination states which is obtained by translating each of states included in the state sets, until the number of states included in the intersection set becomes equal to one, while regarding the set of the transition destination states for each of the input symbol included in the intersection set as new state sets, and plural indistinguishable states are merged into one state by tracing a route in a reverse direction to a transition direction, when the number of states has become equal to one.

Deterministic Finite Automatons (DFAs) and Nondeterministic Finite Automatons (NFAs) are two typical automatons used in the Network Intrusion Detection System (NIDS). Although they both perform regular expression matching, they have quite different performance and memory usage properties. DFAs provide fast and deterministic matching performance but suffer from the well-known state explosion problem. NFAs are compact, but their matching performance is unpredictable and with no worst case guarantee. A new automaton representation of regular expressions, called Tunable Finite Automaton (TFA), is described. TFAs resolve the DFAs' state explosion problem and the NFAs' unpredictable performance problem. Different from a DFA, which has only one active state, a TFA allows multiple concurrent active states. Thus, the total number of states required by the TFA to track the matching status is much smaller than that required by the DFA. Different from an NFA, a TFA guarantees that the number of concurrent active states is bounded by a bound factor b that can be tuned during the construction of the TFA according to the needs of the application for speed and storage. A TFA can achieve significant reductions in the number of states and memory space.

Techniques for data pattern analysis using deterministic finite automaton are described herein. In one embodiment, a number of transitions from a current node to one or more subsequent nodes representing one or more sequences of data patterns is determined, where each of the current node and subsequent nodes is associated with a deterministic finite automaton (DFA) state. A data structure is dynamically allocated for each of the subsequent nodes for storing information associated with each of the subsequent nodes, where data structures for the subsequent nodes are allocated in an array maintained by a data structure corresponding to the current node if the number of transitions is greater than a predetermined threshold. Other methods and apparatuses are also described.

Deterministic Finite Automatons (DFAs) and Nondeterministic Finite Automatons (NFAs) are two typical automatons used in the Network Intrusion Detection System (NIDS). Although they both perform regular expression matching, they have quite different performance and memory usage properties. DFAs provide fast and deterministic matching performance but suffer from the well-known state explosion problem. NFAs are compact, but their matching performance is unpredictable and with no worst case guarantee. A new automaton representation of regular expressions, called Tunable Finite Automaton (TFA), is described. TFAs resolve the DFAs' state explosion problem and the NFAs' unpredictable performance problem. Different from a DFA, which has only one active state, a TFA allows multiple concurrent active states. Thus, the total number of states required by the TFA to track the matching status is much smaller than that required by the DFA. Different from an NFA, a TFA guarantees that the number of concurrent active states is bounded by a bound factor b that can be tuned during the construction of the TFA according to the needs of the application for speed and storage. A TFA can achieve significant reductions in the number of states and memory space.

A method and corresponding apparatus relate to converting a nondeterministic finite automata (NFA) graph for a given set of patterns to a deterministic finite automata (DFA) graph having a number of states. Each of the DFA states is mapped to one or more states of the NFA graph. A hash value of the one or more states of the NFA graph mapped to each DFA state is computed. A DFA states table correlates each of the number of DFA states to the hash value of the one or more states of the NFA graph for the given pattern.

Deterministic Finite Automatons (DFAs) and Nondeterministic Finite Automatons (NFAs) are two typical automatons used in the Network Intrusion Detection System (NIDS). Although they both perform regular expression matching, they have quite different performance and memory usage properties. DFAs provide fast and deterministic matching performance but suffer from the well-known state explosion problem. NFAs are compact, but their matching performance is unpredictable and with no worst case guarantee. A new automaton representation of regular expressions, called Tunable Finite Automaton (TFA), is described. TFAs resolve the DFAs' state explosion problem and the NFAs' unpredictable performance problem. Different from a DFA, which has only one active state, a TFA allows multiple concurrent active states. Thus, the total number of states required by the TFA to track the matching status is much smaller than that required by the DFA. Different from an NFA, a TFA guarantees that the number of concurrent active states is bounded by a bound factor b that can be tuned during the construction of the TFA according to the needs of the application for speed and storage. A TFA can achieve significant reductions in the number of states and memory space.

The invention provides regular expression matching equipment and a method on the basis of a deterministic finite automaton. The regular expression matching equipment comprises a packet dispatcher and a result collecting module. A regular expression matching system comprises a matching unit and a storage unit connected with the matching unit, the matching unit is respectively connected with the packet dispatcher and the result collecting module. In the method, each status transfer table is disintegrated into a character substitution table and a simplified status table, many statuses have identical character substitution tables and can be shared after disintegration, and furthermore, many statuses have identical character substitution tables, and can share the identical character substitution tables after minority skips are extracted. By the regular expression matching equipment and the method on the basis of the deterministic finite automaton, storage space for the DFA (deterministic finite automaton) is greatly reduced, and more regular expressions can be stored in a limited space.