In view of the security problem of smart substation telecontrol communication and the mostly adopted RSA public-key algorithm in the existing security system

a security solution based on IEC-62351-3 is designed. The whole procedure of transport layer secure(TLS)handshaking agreement and the corresponding processing time is calculated. Then

how to solve the problem of overlong connecting time when adopting TLS agreement as the transmission channel by utilizing cache mechanism is analyzed. Finally

a security strategy for smart substation telecontrol communication based on coordination between ‘long connection' and ‘short connection' of SM2 password based TLS agreement is proposed. The total transmission delay is simulated by the synchronous digital hierarchy(SDH)communication network of Jiangsu scheduling center on the OPENET platform

which indicates that the proposed scheme can well satisfy the security and real-time demand. This work is supported by National Development and Reform Commission(No. 〔2012〕1424)

Jiangsu Province Economic and Information Commission(No. 〔2011〕1178)and Wuxi City 2012 Innovation Fund(Technology Support)Project(No. CGE01G1211).