A method of a local bundle assistant (LBA) negotiating a certificate with a secondary platform bundle manager (SPBM) in a wireless communication system including: transmitting a request message requesting information of certificates supported by a secondary secure platform (SSP) to a secondary platform bundle loader (SPBL) of the SSP; receiving the information of certificates supported by the SSP including information of certificate issuers corresponding to a family identifier from the SPBL; transmitting the information of certificates supported by the SSP to the SPBM; and receiving a certificate of the SPBM for key agreement, information of public key identifiers of certificate issuers to be used by the SSP, and information of the family identifier from the SPBM.