A system for secure transfer of digital aircraft data comprising redundant data producer systems includes a first data producer, capable of producing first data, at successive moments, and a second data producer, redundant to the first system. The second data producer is capable of producing an integrity check result relating at least to second data which it produces in a manner redundant to the first data, the integrity check result being transmitted to a data consumer. The data consumer is capable of retrieving the first data and the integrity check result produced by the second system, to produce a new integrity check result from the first data and compare the new integrity check result with the integrity check result produced by the second system.