In this paper, we investigate a security architecture for V2V communication that ensure integrity, confidentiality, anonymity, authenticity and non-repudiation. Based on IEEE 1609.2 Standard, we propose group-based V2V authentication and communication for safety message dissemination with lightweight solution, decentralized via group leaders (GLs), efficient, economical and applicable in real mode. We simulate the existing security solutions using "Estinet" simulator and we show that our group-based authentication proposal performs better than other schemes