An Overview of Cryptography (Updated Version, 3 March 2016)

There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of cryptography...While cryptography is necessary for secure communications, it is not by itself sufficient. This paper describes the first of many steps necessary for better security in any number of situations. A much shorter, edited version of this paper appears in the 1999 edition of Handbook on Local Area Networks published by Auerbach in September 1998

Bootstrapping Secure Multicast using Kerberized Multimedia Internet Keying

We address bootstrapping secure multicast in enterprise and public-safety settings. Our work is motivated by the fact that secure multicast has important applications in such settings, and that the application setting significantly influences the design of security systems and protocols. This document presents and analyzes two designs for the composition of the authentication protocol, Kerberos, and the key transport protocol, Multimedia Internet KEYing (MIKEY). The two designs are denoted to be KM1 and KM2 . The main aspect in which the objective impacts the design is the assumption of an additional trusted third party (called a Key Server) that is the final arbiter on whether a principal is authorized to receive a key. Secure composition can be a challenge, and therefore the designs were kept to be simple so they have intuitive appeal. Notwithstanding this, it was recognized that even simple, seemingly secure protocols can have flaws. Two main security properties of interest called safety and avail- ability were articulated. A rigorous analysis of KM1 and KM2 was conducted using Protocol Composition Logic (PCL), a symbolic approach to analyzing security protocols, to show that the designs have those properties. The value of the analysis is demonstrated by a possible weakness in KM1 that was discovered which lead to the design of KM2 . A prototype of KM1 and KM2 was implemented starting with the publicly available reference implementation of Kerberos, and an open-source implementation of MIKEY. This document also discusses the experience from the implementation, and present empirical results which demonstrate the inherent trade-off between security and performance in the design of KM1 and KM2

Efficient Quantum-Resistant Trust Infrastructure based on HIMMO

Secure Internet communications face conflicting demands: while advances in (quantum) computers require stronger, quantum-resistant cryptographic algorithms, the Internet of Things demands better-performing protocols. Finally, communication links usually depend on a single root-of-trust, e.g., a certification authority which forms a single point-of-failure that is too big of a risk for future systems. This paper addresses these problems by proposing a hybrid infrastructure that combines the quantum-resistant HIMMO key pre-distribution scheme based on multiple Trusted Third Parties with public-key cryptography. During operation, any pair of devices can use private HIMMO key material and public keys to establish a secure and authenticated link, where their public keys are certified beforehand by multiple TTPs, acting as roots of trust. Our solution is resilient to the capture of individual roots of trust without affecting performance, while public-key cryptography provides features such as forward-secrecy. Combining HIMMO identities with public keys enables secure certification of public keys and distribution of HIMMO key material from multiple TTPs, without requiring an out-of-band channel. The infrastructure can be tuned to fit Internet of Things use-cases benefiting from an efficient, non-interactive and authenticated key exchange, or to fit use-cases where the use of multiple TTPs provides privacy safe-guards when lawful interception is required. Our TLS proof-of-concept shows the feasibility of our proposal by integrating the above security features with minimal changes in the TLS protocol. Our TLS implementation provides classic and post-quantum confidentiality and authentication, all while adding a computation overhead of only 2.8% and communication overhead of approximately 50 bytes to a pre-quantum Elliptic Curve Diffie-Hellman ciphersuite

Authentication in Protected Core Networking

Protected Core Networking (PCN) is a concept that aims to increase information sharing between nations in coalition military operations. PCN specifies the interconnection of national transport networks, called Protected Core Segments (PCSs), to a federated transport network called Protected Core (PCore). PCore is intended to deliver high availability differentiated transport services to its user networks, called Colored Clouds (CCs). To achieve this goal, entity authentication of all connecting entities is specified as a protective measure. In resource constrained environments, the distribution of service policy can be challenging. That is, which transport services are associated with a given entity. The thesis proposes two new and original protocols where CCs push service policy to the network by performing authentication based on attributes. Using identity-based signatures, attributes constituting a service policy are used directly for an entity's identity, and no external mechanism linking identity and policy is needed. For interoperability, the idea has been incorporated into PKINIT Kerberos and symmetric key Kerberos by carrying the authorized attributes within tickets. The proposed protocols are formally verified in the symbolic model using scyther-proof. The experiment shows that both CCs, and PCSs achieve greater assurance on agreed attributes, and hence on expected service delivery. A CC and a visiting PCS are able to negotiate, and agree on the expected service depending on the situation. The proposed solution provides benefits to CCs on expected service when connecting to a visiting PCS, with poor connectivity to the home PCS. In that respect, interconnection of entities with little pre-established relationship is simplified, and hence fulfillment of the PCN concept is facilitated

Analysing the behaviour of a smart card based model for secure communication with remote computers over the internet

This dissertation presents the findings of a generic model aimed at providing secure communication with remote computers via the Internet, based on smart cards. The results and findings are analysed and presented in great detail, in particular the behaviour and performance of smart cards when used to provide the cryptographic functionality. Two implemented models are presented. The first model uses SSL to secure the communication channel over the Internet while using smart cards for user authentication and storage of cryptographic keys. The second model presents the SSH for channel security and smart cards for user authentication, key storage and actual encryption and decryption of data. The model presented is modular and generic by nature, meaning that it can easily be modified to accept the newer protocol by simply including the protocols in a library and with a minor or no modification to both server and client application software. For example, any new algorithm for encryption, key exchange, signature, or message digest, can be easily accommodated into the system, which proves that the model is generic and can easily be integrated into newer technologies. Similarly, smart cards are used for cryptography. Two options are presented: first the smart cards only store the algorithm keys and user authentication, and secondly, smart cards are used for storing the algorithm keys, user authentication, and actual data encryption or decryption, as the requirement may dictate. This is very useful, for example, if data to be transferred is limited to a few bytes, then actual data encryption and decryption is performed using smart cards. On the other hand, if a great deal of data is to be transferred, then only authentication and key storage are performed with smart cards. The model currently uses 3DES with smart card encryption and decryption, because this is faster and consumes fewer resources when compared to RSA. Once again, the model design is flexible to accommodate new algorithms such as AES or IDEA. Important aspects of the dissertation are the study and analysis of the security attacks on smart card use. Several smart card attack scenarios are presented in CHAPTER 3, and their possible prevention is also discussed in detail. AFRIKAANS : Hierdie verhandeling bied die bevindinge van 'n generiese model wat daarop gemik is om veilige kommunikasie te voorsien met 'n afstandsrekenaar via die Internet en op slimkaarte gebaseer. Die resultate en bevindings word ontleed en breedvoerig aangebied, veral die gedrag en werkverrigting van slimkaarte wanneer hulle gebruik word om die kriptografiese funksionaliteit te voorsien. Daar word twee geïmplementeerde modelle aangebied. Die eerste model gebruik SSL om die kommunikasiekanaal oor die Internet te beveilig terwyl slimkaarte vir gebruikerbekragtiging en stoor van kriptografiese sleutels gebruik word. Die tweede model bied die SSH vir kanaalsekuriteit en slimkaarte vir gebruikergeldigheidvasstelling, sleutelstoor en werklike kodering en dekodering van data. Die model wat aangebied word, is modulêr en generies van aard, wat beteken dat dit maklik gewysig kan word om die jongste protokolle te aanvaar deur bloot die protokolle by 'n programbiblioteek met geringe of geen wysiging van beide die bediener- en kliënttoepassingsagteware in te sluit. Byvoorbeeld, enige nuwe algoritme vir kodering, sleuteluitruiling, handtekening of boodskapbondeling kan maklik in die stelsel gehuisves word, wat bewys dat die model generies is en maklik in jonger tegnologieë geïntegreer kan word. Slimkaarte word op soortgelyke wyse vir kriptografie gebruik. Daar word twee keuses aangebied: eerstens stoor die slimkaarte slegs die algoritmesleutels en gebruikergeldigheidvasstelling en tweedens word slimkaarte gebruik om die algoritmesleutels, gebruikergeldigheidvasstelling en werklike datakodering en –dekodering te stoor na gelang van wat vereis word. Dit is baie nuttig, byvoorbeeld, wanneer data wat oorgedra moet word, tot 'n paar grepe beperk is, word die eintlike datakodering en – dekodering uitgevoer deur slimkaarte te gebruik. Andersyds, indien 'n groot hoeveelheid data oorgedra moet word, word slegs geldigheidvasstelling en stoor met slimkaarte uitgevoer. Die model gebruik tans 3DES met slimkaartkodering en –dekodering omdat dit vinniger is en minder hulpbronne gebruik vergeleke met RSA. Die modelontwerp is weer eens buigsaam om nuwe algoritmes soos AES of IDEA te huisves. Nog 'n belangrike aspek van die verhandeling is om die sekuriteitaanvalle op slimkaartgebruik te ondersoek en te ontleed. Verskeie slimkaartaanvalscenario's word in Hoofstuk 3 aangebied en die moontlike voorkoming daarvan word ook breedvoerig bespreek.Dissertation (MEng)--University of Pretoria, 2011.Electrical, Electronic and Computer Engineeringunrestricte

SECURITY MEASUREMENT FOR LTE/SAE NETWORK DURING SINGLE RADIO VOICE CALL CONTINUITY (SRVCC).

Voice has significant place in mobile communication networks. Though data applications have extensively gained in importance over the years but voice is still a major source of revenue for mobile operators. It is obvious that voice will remain an important application even in the era of Long Term Evolution (LTE). Basically LTE is an all-IP data-only transport technology using packet switching. Therefore, it introduces challenges to satisfy quality of service expectations for circuit-switched mobile telephony and SMS for LTE capable smartphones, while being served on the LTE network. Since 2013, mobile operators have been busy deploying Voice Over LTE (VoLTE). They are relying on a VoLTE technology called Single Radio Voice Call Continuity (SRVCC) for seamless handover between packet-switch domain to circuit-switch domain or vice versa. The aim of thesis is to review and identify the security measurement during SRVCC and verify test data for ciphering and integrity algorithm.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Towards a model for ensuring optimal interoperability between the security systems of trading partners in a business-to-business e-commerce context

A vast range of controls/countermeasures exists for implementing security on information systems connected to the Internet. For the practitioner attempting to implement an integrated solution between trading partners operating across the Internet, this has serious implications in respect of interoperability between the security systems of the trading partners. The problem is exacerbated by the range of specification options within each control. This research is an attempt to find a set of relevant controls and specifications towards a framework for ensuring optimal interoperability between trading partners in this context. Since a policy-based, layered approach is advocated, which allows each trading partner to address localized risks independently, no exhaustive risk analysis is attempted. The focus is on infrastructure that is simultaneously optimally secure and provides optimal interoperability. It should also be scalable, allowing for additional security controls to be added whenever deemed necessary.ComputingM. Sc. (Information Systems