In this paper, we present the design of a cryptographic core compliant with the IEEE 802.15.4 standard and based on FPGA. We have addressed several security problems that remain yet problematic concerning the implementation of the 802.15.4 security suites and the access control list (ACL). The cryptographic core consists of three components: a compact AES-CCM architecture, a content-addressable memory (CAM) that implements an access control list (ACL) and a modular exponentiation unit based on Montgomery arithmetic. The modular exponentiation core can be used to perform key agreement based on a variant of the Diffie-Hellman Key Exchange (DHKE). The core has been synthesized in a Spartan-6 xc6slx75-3csg484 FPGA built on a 45 nm process. The total logic usage of the FPGA was 71 %.