A gateway for exchanging information between processing units, each piece of information being associated with its own level of criticality, each processing unit being defined by a respective level of criticality, each processing unit being suitable for processing only information having a level of criticality lower than or equal to the level of criticality of the processing unit considered, the gateway comprising a filter with which a level of criticality is associated for each level of criticality present in the information exchanged between the processing units, the set of levels of criticality being between 1 and N, N being an integer greater than or equal to 2, each filter comprising: - a first information sub-filter with which a first level of criticality is associated, the first sub-filter being suitable for classifying incident information into two categories, a first category grouping information having a level of criticality equal to the first level of criticality and a second category grouping the information having a level of criticality different from the first level of criticality, - a second information sub-filter with which is associated a second level of criticality, the second sub-filter being able to classify incident information into two categories, a first category grouping information having a level of criticality equal to the second level of criticality and a second category grouping information having a level of criticality different from the second level of criticality, the second sub-filter being connected to the first sub-filter so that the incident information of the second sub-filter is the information of the second category of the first sub-filter, the first level of criticality and the second level of criticality depending on the level of criticality of the filter, - a unit for eliminating information from the first category of the second sub-filter, and - two post-processing stages (28, 30), each post-processing stage (28, 30) comprising at least one unit chosen from the list consisting of an incident information format adapter and a firewall, the first sub-filter and the second sub-filter comprising first outputs (22S1, 24S1) whereby the information of the first category comes out and second outputs (22S2, 24S2) whereby the information of the second category comes out, the second output (22S2) of the first sub-filter being connected to the first post-processing stage and the second output (24S2) of the second sub-filter being connected to the first post-processing stage, and the first post-processing stage of each filter being connected to processing units authorized to process the information output from the filter. - a first information sub-filter with which a first level of criticality is associated, the first sub-filter being suitable for classifying incident information into two categories, a first category grouping information having a level of criticality equal to the first level of criticality and a second category grouping the information having a level of criticality different from the first level of criticality, - a second information sub-filter with which is associated a second level of criticality, the second sub-filter being able to classify incident information into two categories, a first category grouping information having a level of criticality equal to the second level of criticality and a second category grouping information having a level of criticality different from the second level of criticality, the second sub-filter being connected to the first sub-filter so that the incident information of the second sub-filter is the information of the second category of the first sub-filter, the first level of criticality and the second level of criticality depending on the level of criticality of the filter, the second sub-filter being connected to the first sub-filter so that the incident information of the second sub-filter is the information of the second category of the first sub-filter, the first level of criticality and the second level of criticality depending on the level of criticality of the filter, - a unit for eliminating information from the first category of the second sub-filter, and - two post-processing stages (28, 30), each post-processing stage (28, 30) comprising at least one unit chosen from the list consisting of an incident information format adapter and a firewall, the first sub-filter and the second sub-filter comprising first outputs (22S1, 24S1) whereby the information of the first category comes out and second outputs (22S2, 24S2) whereby the information of the second category comes out, the second output (22S2) of the first sub-filter being connected to the first post-processing stage and the second output (24S2) of the second sub-filter being connected to the first post-processing stage, and the first post-processing stage of each filter being connected to processing units authorized to process the information output from the filter. the first sub-filter and the second sub-filter comprising first outputs (22S1, 24S1) whereby the information of the first category comes out and second outputs (22S2, 24S2) whereby the information of the second category comes out, the second output (22S2) of the first sub-filter being connected to the first post-processing stage and the second output (24S2) of the second sub-filter being connected to the first post-processing stage, and the first post-processing stage of each filter being connected to processing units authorized to process the information output from the filter.