As the implementations of the Bundle Protocol (RFC 5050) reach remarkable maturity, an increased interest is now appearing to fully implement the DTN security features as specified in the Bundle Security Protcol (RFC 6257). In this regard, in this paper we present our BSP implementation suitable for embedded devices with scarce resources (limited prcocessing, memory, energy and transmission capabilities). Our BSP implementation enhances the existing security features in DTN2(v2.8). We analyze the functionality and the performance of our secure DTN2 stack via experimental means. Namely, we conducted a series of test cases in our heterogeneous TCP/IP-based test-bed. The latter allowed for experimentation regarding bundle transmission via different network interfaces (high bit-rate wire-line and low bit-rate wireless links) and with different types of interconnected DTN-enabled devices. The results prove that the security developments impose tolerable communication overhead and reveal the DTN performance factors.