Formally based semi-automatic implementation of an open security protocol

International audienceThis paper presents an experiment in which an implementation of the client side of the SSH Transport Layer Protocol (SSH-TLP) was semi-automatically derived according to a model-driven development paradigm that leverages formal methods in order to obtain high correctness assurance. The approach used in the experiment starts with the formalization of the protocol at an abstract level. This model is then formally proved to fulfill the desired secrecy and authentication properties by using the ProVerif prover. Finally, a sound Java implementation is semi-automatically derived from the verified model using an enhanced version of the Spi2Java framework. The resulting implementation correctly interoperates with third party servers, and its execution time is comparable with that of other manually developed Java SSH-TLP client implementations. This case study demonstrates that the adopted model-driven approach is viable even for a real security protocol, despite the complexity of the models needed in order to achieve an interoperable implementation

Comparison of different ways to avoid internet traffic interception

Projecte fet en col.laboració amb la Norwegian University of Science and Technology. Department of Telematic EngineeringEnglish: The main objective of this thesis is to analyze and compare different ways to avoid the Internet traffic eavesdropping (carried out both by governments or malicious particulars). The analysis consists on a description of the different protocols and technologies involved in each option as well as the difficulties to implement them and the technical knowledge of the users in order to take profit of them

Flexible and Scalable Public Key Security for SSH

A standard tool for secure remote access, the SSH protocol uses public-key cryptography to establish an encrypted and integrity-protected channel with a remote server. However, widely-deployed implementations of the protocol are vulnerable to man-in-the-middle attacks, where an adversary substitutes her public key for the server\u27s. This danger particularly threatens a traveling user Bob borrowing a client machine. Imposing a traditional X.509 PKI on all SSH servers and clients is neither flexible nor scalable nor (in the foreseeable future) practical. Requiring extensive work or an SSL server at Bob\u27s site is also not practical for many users. This paper presents our experiences designing and implementing an alternative scheme that solves the public-key security problem in SSH without requiring such an a priori universal trust structure or extensive sysadmin work--although it does require a modified SSH client. (The code is available for public download.

Cloud Storage Performance and Security Analysis with Hadoop and GridFTP

Even though cloud server has been around for a few years, most of the web hosts today have not converted to cloud yet. If the purpose of the cloud server is distributing and storing files on the internet, FTP servers were much earlier than the cloud. FTP server is sufficient to distribute content on the internet. Therefore, is it worth to shift from FTP server to cloud server? The cloud storage provider declares high durability and availability for their users, and the ability to scale up for more storage space easily could save users tons of money. However, does it provide higher performance and better security features? Hadoop is a very popular platform for cloud computing. It is free software under Apache License. It is written in Java and supports large data processing in a distributed environment. Characteristics of Hadoop include partitioning of data, computing across thousands of hosts, and executing application computations in parallel. Hadoop Distributed File System allows rapid data transfer up to thousands of terabytes, and is capable of operating even in the case of node failure. GridFTP supports high-speed data transfer for wide-area networks. It is based on the FTP and features multiple data channels for parallel transfers. This report describes the technology behind HDFS and enhancement to the Hadoop security features with Kerberos. Based on data transfer performance and security features of HDFS and GridFTP server, we can decide if we should replace GridFTP server with HDFS. According to our experiment result, we conclude that GridFTP server provides better throughput than HDFS, and Kerberos has minimal impact to HDFS performance. We proposed a solution which users authenticate with HDFS first, and get the file from HDFS server to the client using GridFTP

A survey of the interaction between security protocols and transport services

This document provides a survey of commonly used or notable network security protocols, with a focus on how they interact and integrate with applications and transport protocols. Its goal is to supplement efforts to define and catalog Transport Services by describing the interfaces required to add security protocols. This survey is not limited to protocols developed within the scope or context of the IETF, and those included represent a superset of features a Transport Services system may need to support

Assessment and hardening of IOT development boards

© IFIP International Federation for Information Processing 2019. Internet of Things (IoT) products became recently an essential part of any home in conjunction with the great advancements in internet speeds and services. The invention of IoT based devices became an easy task that could be performed through the widely available IoT development boards. Raspberry Pi is considered one of the advanced development boards that have high hardware capabilities with a reasonable price. Unfortunately, the security aspect of such products is overlooked by the developers, revealing a huge amount of threats that result in invading the privacy and the security of the users. In this research, we directed our study to SSH due to its extensive adoption by the developers. It was found that due to the nature of the Raspberry Pi and development boards, the Raspberry Pi generates predictable and weak keys which make it easy to be utilized by MiTM attack. In this paper, Man in The Middle (MiTM) attack was conducted to examine the security of different variations provided by the SSH service, and various hardening approaches were proposed to resolve the issue of SSH weak implementation and weak keys

Deploying a New Hash Algorithm

The strength of hash functions such as MD5 and SHA-1 has been called into question as a result of recent discoveries. Regardless of whether or not it is necessary to move away from those now, it is clear that it will be necessary to do so in the not-too-distant future. This poses a number of challenges, especially for certificate-based protocols. We analyze a number of protocols, including S/MIME and TLS. All require protocol or implementation changes. We explain the necessary changes, show how the conversion can be done, and list what measures should be taken immediately

Honeypots in the age of universal attacks and the Internet of Things

Today's Internet connects billions of physical devices. These devices are often immature and insecure, and share common vulnerabilities. The predominant form of attacks relies on recent advances in Internet-wide scanning and device discovery. The speed at which (vulnerable) devices can be discovered, and the device monoculture, mean that a single exploit, potentially trivial, can affect millions of devices across brands and continents. In an attempt to detect and profile the growing threat of autonomous and Internet-scale attacks against the Internet of Things, we revisit honeypots, resources that appear to be legitimate systems. We show that this endeavour was previously limited by a fundamentally flawed generation of honeypots and associated misconceptions. We show with two one-year-long studies that the display of warning messages has no deterrent effect in an attacked computer system. Previous research assumed that they would measure individual behaviour, but we find that the number of human attackers is orders of magnitude lower than previously assumed. Turning to the current generation of low- and medium-interaction honeypots, we demonstrate that their architecture is fatally flawed. The use of off-the-shelf libraries to provide the transport layer means that the protocols are implemented subtly differently from the systems being impersonated. We developed a generic technique which can find any such honeypot at Internet scale with just one packet for an established TCP connection. We then applied our technique and conducted several Internet-wide scans over a one-year period. By logging in to two SSH honeypots and sending specific commands, we not only revealed their configuration and patch status, but also found that many of them were not up to date. As we were the first to knowingly authenticate to honeypots, we provide a detailed legal analysis and an extended ethical justification for our research to show why we did not infringe computer-misuse laws. Lastly, we present honware, a honeypot framework for rapid implementation and deployment of high-interaction honeypots. Honware automatically processes a standard firmware image and can emulate a wide range of devices without any access to the manufacturers' hardware. We believe that honware is a major contribution towards re-balancing the economics of attackers and defenders by reducing the period in which attackers can exploit vulnerabilities at Internet scale in a world of ubiquitous networked `things'.Premium Research Studentship, Department of Computer Science and Technology, University of Cambridg

Poikkeamien havainnointi sieppausvälityspalvelimissa

Use of interception proxies is becoming more popular. They are used to audit access and enforce policies and constraints to important servers or whole network segments. The sheer amount of data captured with the devices makes fully manual pruning of the data impractical. Methods to analyze the gathered data to highlight possible attacks or problems would be valuable in freeing up administrator time and resources. This thesis investigates the use of clustering methods to identify anomalous connections, either by identifying them as outliers or bundling them with other connections which have raised alarm in the past. The work shows that a practical approach can be implemented with a DBSCAN-based clustering method, but concluded that an unsupervised approach is not enough. As a semisupervised method the system can have value in production environments.Sieppausvälityspalvelimien käyttö on yleistymässä. Niitä käytetään käytäntöjen ja rajoitusten täytäntöönpanossa sekä kriittisten palvelimien ja verkon osien käytön valvomisessa. Laitteiden kaappaaman tiedon määrä on niin valtava, että tiedon purkaminen manuaalisesti on epäkäytännöllistä. Menetelmät jotka analysoivat dataa mahdollisten hyökkäysten tai ongelmien esiin nostamiseksi olisivat hyvin arvokkaita vapauttamaan järjestelmänvalvojien aikaa ja resursseja. Tässä työssä tutkitaan ryhmittelyalgoritmien käyttökelpoisuutta epätavallisten yhteyksien havainnoimisessa joko tunnistamalla ne poikkeaviksi, koska ne eivät kuulu mihinkään ryhmään tai asettamalla ne samaan ryhmään sellaisen yhteyden kanssa joka on todettu hälyttäväksi aiemmin. Työssä todetaan, että käytännöllinen sovellus järjestelmästä voidaan toteuttaa käyttäen DBSCAN-pohjaista ryhmittelyalgoritmia, mutta täysin valvomattomalla lähestymistavalla ei saada riittävän hyvää tulosta. Osittain valvottuna menetelmästä voi olla hyötyä tuotantojärjestelmien valvonnassa