Securing blockchain access through a gateway on behalf of a communication device

For securing a blockchain access through a gateway (GAT) on behalf of a communication device (CD) in a wireless telecommunication network (TN), an apparatus (AM) operating with the gateway:receives a request (Req) sent from a communication device (CD) through the gateway (GAT), the request containing an identifier (IdCD) of the communication device, an identifier (IdR) of the request and a key (K),checks a distributed blockchain that includes information regarding the communication device and that is stored in a first blockchain network (BN1) and retrieving a value (V) corresponding to the key (K),creates a smart contract based on the key (K), the value (V), a timestamp (T), the identifier (IdCD) of the communication device, and the identifier (IdR) of the request, the smart contract being defined to confirm the validity of value (V) corresponding to the key (K) in the first blockchain network (BN1),appends the smart contract to a second blockchain network (BN2), the smart contract having to be executed on the first blockchain network (BN1) by at least one validator having access to the first blockchain network (BN1) and second blockchain network (BN2),signs a response (Res) containing the key (K), the value (V), and the identifier (IdR) of the request with a certificate (Cert),sends the response (Res) to the communication device (CD) through the gateway (GAT).