With the popularity of wireless communication devices a new important dimension of embedded systems design has arisen, that of security. This paper presents for the first time design exploration for secure implementation of cryptographic applications on a complex DSP processor core. A new metric for security, the implementation security index, is introduced for measuring resistance to power attacks. Elliptic curve cryptographic algorithms are used to demonstrate and quantize security, energy, performance and code size tradeoffs. Modification of power traces is performed to maximize security against power attacks which has significant savings in energy dissipation compared to an existing mathematical approach. This research is important for industry since efficient yet secure cryptography is crucial for wireless communication embedded system devices.