383 research outputs found

    Secure Bitcoin Wallet

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    Virtuaalvaluutad ja mobiilne pangandus on tehnoloogilised uuendused, mis on rah- vusvahelises kogukonnas saamas kasvavat tähelepanu oma kättesaadavuse, mugavuse ja kiiruse tõttu. Populaarsuse kasv on kahjuks kaasa toonud ka suurenenud turvariski iden- titeedivarguste näol, tekitades ohu kasutajate anonüümsusele. Riske on võimalik vältida, kasutades krüptograafilisi meetmeid Bitcoini ja teiste hajutatud digitaalsete valuutade vastaste rünnete vähendamiseks sideliinil ning hoiustamisel. See ülevaade koondab erine- vad meetodid ja lahendused selliste rünnete vastu ning uurib nende tõhusust. Lisaks kir- jeldatakse turvalist Bitcoini rahakotti (Secure Bitcoin Wallet), mis on standardne Bitcoini ülekannete klient koos tõhustatud turvaomaduste ja -teenustega.Virtual currencies and mobile banking are technology advancements that are receiving increased attention in the global community because of their accessibility, convenience and speed. However, this popularity comes with growing security concerns, like increasing frequency of identity theft, leading to bigger problems which put user anonymity at risk. One possible solution for these problems is using cryptography to enhance security of Bitcoin or other decentralised digital currency systems and to decrease frequency of attacks on either communication channels or system storage. This report outlines various methods and solutions targeting these issues and aims to understand their effectiveness. It also describes Secure Bitcoin Wallet, standard Bitcoin transactions client, enhanced with various security features and services

    Enabling Use of Signal in a Disconnected Village Environment

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    A significant portion of the world still does not have a stable internet connection. Those people should have the ability to communicate with their loved ones who may not live near by or to share ideas with friends. To power this achievable reality, our lab has set out on making infrastructure for enabling delay tolerant applications. This network will communicate using existing smartphones that will relay the information to a connected environment. The proof of concept application our lab is using is Signal as it offers end to end encryption messaging and an open source platform our lab can develop

    Alpenhorn: Bootstrapping Secure Communication without Leaking Metadata

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    Alpenhorn is the first system for initiating an encrypted connection between two users that provides strong privacy and forward secrecy guarantees for metadata (i.e., information about which users connected to each other) and that does not require out-of-band communication other than knowing the other user's Alpenhorn username (email address). This resolves a significant shortcoming in all prior works on private messaging, which assume an out-of-band key distribution mechanism. Alpenhorn's design builds on three ideas. First, Alpenhorn provides each user with an address book of friends that the user can call to establish a connection. Second, when a user adds a friend for the first time, Alpenhorn ensures the adversary does not learn the friend's identity, by using identity-based encryption in a novel wayto privately determine the friend's public key. Finally, when calling a friend, Alpenhorn ensures forward secrecy of metadata by storing pairwise shared secrets in friends' address books, and evolving them over time, using a new keywheel construction. Alpenhorn relies on a number of servers, but operates in an anytrust model, requiring just one of the servers to be honest. We implemented a prototype of Alpenhorn, and integrated it into the Vuvuzela private messaging system (which did not previously provide privacy or forward secrecy of metadata when initiating conversations). Experimental results show that Alpenhorn can scale to many users, supporting 10 million users on three Alpenhorn servers with an average call latency of 150 seconds and a client bandwidth overhead of 3.7 KB/sec

    Secure and insecure chat implementation

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    MobilitatInternet is not a single network, but a worldwide collection of loosely connected networks that are accessible by using computers, smartphones or tablets, in a variety of ways, to anyone with a computer and a network connection. Thus, individuals and organizations can reach any point on the internet without regard to national or geographic boundaries or time of day. However, along with the convenience and easy access to information come risks. Among them are the risks that valuable information will be lost, stolen, changed, or misused. If information is recorded electronically and is available on networked computers, it is more vulnerable than if the same information is printed on paper and locked in a file cabinet. Intruders do not need to enter an office or home, they may not even be in the same country. They can steal or tamper with information without touching a piece of paper or a photocopier. They can also create new electronic files, run their own programs, and hide evidence of their unauthorized activity. As it can be seen, securities issues are of a high relevance because Internet is a network of networks in which the information sent can travel over a secure or insecure network. Nowadays, messaging or chat applications are used every day by millions of users to exchange text messages, pictures, videos, contacts, documents and so on. It is translated to a huge amount of data travelling by the network in a transparent way for the users involved. For all this reasons, applying security to the information sent is really important to guarantee data protection. In our case, it has been desired to implement a chat application in which a Server and a Client can exchange, for instance, messages, pictures, documents, songs, and videos. In this application, both entities should have the possibility of sending the information over a secure or insecure channel. If the secure way is chosen some cryptographic protocols, such as symmetric and asymmetric cryptography methods, will be applied to guarantee the most important security aspects: confidentiality, security, reliability and no repudiation. In the insecure way, any cryptographic method is applied and the information will be sent in clear. To be able to exchange messages and several types of documents, it is desired to implement an interface using JAVA language in which an option has to offer to the user the possibility of switching between the secure and insecure channel. Moreover, this interface should have a box in which to store the information sent and received and a copy of this information should be stored in a backup file for further treatment. After that, it is desired to compare the packets sent and received over the local loop using Wireshark tool to verify how the information is sent when using the secure and insecure way

    Implementation of an identity based encryption sub-system for secure e-mail and other applications

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    This thesis describes the requirements for, and design of, a suite of a sub-systems which support the introduction of Identity Based Encryption (IBE) to Intrenet communications. Current methods for securing Internet transmission are overly complex to users and require expensive and complex supporting infrastructure for distributing credentials such as certificates or public keys. Identity Based Encryption holds a promise of simplifying the process without compromising the security. In this thesis I will outline the theory behind the cryptography required , give a background to e-M ail and messaging protocols,the current security methods, the infrastructure used, the issues with these methods, and the break through that recent innovations in Identity Based Encryption hopes to deliver.I will describe an implementation of a sub-system that secures e-Mail and other protocolsin desktop platforms with as little impact on the end user as possible
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