Abstract: Provided are a system and method for allocating an Internet protocol version 4 (IPv4) address through authentication of a dual stack transition mechanism (DSTM) node in a DSTM communication network, DSTM being an IPv4/IPv6 address translation mechanism. The system and method perform authentication when an IPv4 address is allocated between a DSTM node and the DSTM server in the DSTM communication network. According to the system and method, when the DSTM node requests IPv4 address allocation, the DSTM server authenticates the DSTM node, and then allocates an IPv4 address. Therefore, it is possible to solve a problem of exhaustion of an IPv4 address pool of the DSTM server by a denial of service (DoS) attack, as well as potentially solve a security problem of an IPv4/IPv6 translation process.