This paper presents the modelling process and first analysis results carried out within the NEOPPOD project. A protocol, NEO, has been designed in order to manage very large distributed databases such as those used for banking and e-government applications, and thus to handle sensitive data. Security of data is therefore a critical issue that must be ensured before the software can be released on the market. Our project aims at verifying essential properties of the protocol so as to guarantee such properties are satisfied. The model was designed by reverse-engineering from the source code, and then initial verification was performed. This modelling work requires choices of adequate abstraction levels both at the modelling and verification stages. In particular, the overall system is so large that the model should be carefully built in order to make verification possible without getting too far from the actual protocol implementation. This paper focuses on the modelling and initial validation of the election process launched at the system initialisation.