FRAMEWORK FOR ANONYMIZED COVERT COMMUNICATIONS: A BLOCKCHAIN-BASED PROOF-OF-CONCEPT

In this dissertation, we present an information hiding approach incorporating anonymity that builds on existing classical steganographic models. Current security definitions are not sufficient to analyze the proposed information hiding approach as steganography offers data privacy by hiding the existence of data, a property that is distinct from confidentiality (data existence is known but access is restricted) and authenticity (data existence is known but manipulation is restricted). Combinations of the latter two properties are common in analyses, such as Authenticated Encryption with Associated Data (AEAD), yet there is a lack of research on combinations with steganography. This dissertation also introduces the security definition of Authenticated Stegotext with Associated Data (ASAD), which captures steganographic properties even when there is contextual information provided alongside the hidden data. We develop a hierarchical framework of ASAD variants, corresponding to different channel demands. We present a real-world steganographic embedding scheme, Authenticated SteGotex with Associated tRansaction Data (ASGARD), that leverages a blockchain-based application as a medium for sending hidden data. We analyze ASGARD in our framework and show that it meets Level-4 ASAD security. Finally, we implement ASGARD on the Ethereum platform as a proof-of-concept and analyze some of the ways an adversary might detect our embedding activity by analyzing historical Ethereum data.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

BLOCKCHAIN FOR USE IN COLLABORATIVE INTRUSION DETECTION SYSTEMS

As the threat of cyber attack grows ever larger, new approaches to security are required. While there are several different types of intrusion detection systems (IDS), collaborative IDS (CIDS) offers particular promise in identifying distributed, coordinated attacks that might otherwise elude detection. Even for this type of IDS, there are unresolved issues associated with trusting participants and aggregating data. Blockchain technology appears capable of addressing those issues. This thesis is focused on presenting a proof-of-concept experiment leveraging an Ethereum-based private blockchain for a CIDS that uses pluggable authentication modules (PAM) to track login activity toward detection of doorknob rattling attacks.http://archive.org/details/blockchainforuse1094563465Outstanding ThesisLieutenant, United States NavyApproved for public release; distribution is unlimited

Adenoid cystic carcinoma – Solid variant

Adenoid cystic carcinoma (ACC) accounts for about 1% of all head and neck malignancies and 6–10% of all salivary gland neoplasms. ACC is a rare slow growing salivary gland neoplasm with a high recurrence rate. It can occur in any salivary gland site, but approximately 50–60% develop within the minor salivary glands especially palate. Rarely, ACC arising intraosseously have also been reported. ACC is characterized for its wide local infiltration, perineural spread, local recurrence, and distant metastasis. Pain is a common and important finding, occurring early in the course of the disease before there is a noticeable swelling, which is mainly due to neoplastic cell neurotropism. This report describes a case of ACC in the left posterolateral portion of the hard palate in a 36-year-old woman, along with review of literature on ACC