Geometric trees are characterized by their tree-structured layout and spatially constrained nodes and edges, which significantly impacts their topological attributes. This inherent hierarchical structure plays a crucial role in domains such as neuron morphology and river geomorphology, but traditional graph representation methods often overlook these specific characteristics of tree structures. To address this, we introduce a new representation learning framework tailored for geometric trees. It first features a unique message passing neural network, which is both provably geometrical structure-recoverable and rotation-translation invariant. To address the data label scarcity issue, our approach also includes two innovative training targets that reflect the hierarchical ordering and geometric structure of these geometric trees. This enables fully self-supervised learning without explicit labels. We validate our method's effectiveness on eight real-world datasets, demonstrating its capability to represent geometric trees.

Two major schools have dominated computer security research and thinking for the last twenty to twenty-five years -formalism and pragmatism.In spite of all their work, progress has been limited, system designers do not incorporate security principles and security is seen as a detriment to functionality.This paper suggests that an architectural approach, fostered by better communication among security researchers and between the security and operational communities, may yield more practical and effective security solutions.These axhitectural solutions are not totally general, but they have a structure and are applicable to large classes of problems.Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or dktrihuted for profit or commercial advantage and that copies hear this notice and the full citation on the first page.To copy otherwise, to republish, to post on servers or to redis+ihute to lists, requires prior specific permission and/or a fee.

Most security policies and mechanisms ure concerned with controlling the dissemination of information or assuring its integrit.v.System management policies emphusize allocating resourcesfairly.Combining techniques from security and management can allow us to develop countermeasures aguinst many of the network attucks on our systems.In particular, security policies and mechanisms need to be extended to manage resources quantitatively, as well as in a binary manner.The question is not whether access to service is allowed or not, but how to pruvide all the uuthorized services to the limit allowed by the cupucity of the system.This paper explores the idea of ullocating time-limited resources to deter or counter attucks that can cause the system to overload or crash.These overloads can cause not only loss of system availubility to legitimate, well-behaved users, but also loss of system integrity und information security.

Suggests the possibility of controlling the rate of release of information as well as whether the information can be released at all. If the user must have access to information but does not require fast access to large amounts of data, the system can release the information to that user in a slow and unhelpful manner. The addition of the parameter of time acts as a deterrent to information collectors and intruders; less information is available, and the user must access the system repeatedly and for a longer time to get it. Investigation of the rate of release has led to further understanding of the principle of least privilege. The principle of least privilege has generally been espoused by the computer security community as highly desirable. It has been applied to computer security, but only in limited ways. Consideration of time allows a refinement of the concept and offers the possibility of more flexible and fine-grained control.

Although network security theory forbids many connections to large networks as being too risky, the reality is that large numbers of sensitive systems are connected to the Internet and that connectivity is increasing at a rapid rate. Firewalls and host protection mechanisms are used in a somewhat arbitrary fashion, depending more on the availability of products than on a clear understanding of security principles. We need to expand security theory to protect large networks. This paper proposes a new paradigm for security in large networks, based on an understanding of the sometimes conflicting requirements for security, connectivity and functionality. The paradigm, called FICS-IT (Functional, Information, and Connection Security for Information Technology), consists of a philosophy, an approach, a framework and a collection of components. It is based on an understanding of security as risk management and includes: local resource control; multiple, tailored security policies; layered, functional access control; and recognition of heterogeneity in architecture, ownership and policy.

Both network-layer and transport-layer encryption are permitted by the OSI Security Addendum. The advantages of network-layer encryption are discussed. Secure data network system (SDNS) protocols are described. In the SDNS, SP is a single, simple encryption protocol between end-systems. This protocol has two descriptions, SP3 (network layer) and SP4 (transport layer). Both definitions are OSI compliant. Extensions of the basic protocol allow SP3 to be used at intermediate systems and allow SP4 to provide a more connection-oriented service.>