Summarization: Low-power and lossy networks (LLNs) are continually gaining popularity, due to their wide range of applications. Such networks mainly comprise of resource-constrained devices that feature Internet connectivity. This raises many security concerns that cannot be easily resolved, since the inherent limitations of LLN nodes do not allow the direct applicability of existing solutions. This paper proposes an IPsec header compression format for the 6LoWPAN adaptation layer that runs over IEEE802.15.4. The proposed scheme utilises AES-CCM* (CCM-Star), a cryptographic functionality supported by the underlying IEEE802.15.4 protocol, features low packet overhead, and provides both message authentication and confidentiality.Παρουσιάστηκε...