Remote attestation mechanism for embedded devices based on physical unclonable functions

Remote attestation mechanisms are well studied in the high-end computing environments; however, the same is not true for embedded devices-especially for smart cards. With ever changing landscape of smart card technology and advancements towards a true multi-application platform, verifying the current state of the smart card is significant to the overall security of such proposals. The initiatives proposed by GlobalPlatform Consumer Centric Model (GP-CCM) and User Centric Smart Card Ownership Model (UCOM) enables a user to download any application as she desire-depending upon the authorisation of the application provider. Before an application provider issues an application to a smart card, verifying the current state of the smart card is crucial to the security of the respective application. In this paper, we analyse the rationale behind the remote attestation mechanism for smart cards, and the fundamental features that such a mechanism should possess. We also study the applicability of Physical Unclonable Functions (PUFs) for the remote attestation mechanism and propose two algorithms to achieve the stated features of remote attestation. The proposed algorithms are implemented in a test environment to evaluate their performance. © 2013 The authors and IOS Press. All rights reserved

Tree-formed Verification Data for Trusted Platforms

The establishment of trust relationships to a computing platform relies on validation processes. Validation allows an external entity to build trust in the expected behaviour of the platform based on provided evidence of the platform's configuration. In a process like remote attestation, the 'trusted' platform submits verification data created during a start up process. These data consist of hardware-protected values of platform configuration registers, containing nested measurement values, e.g., hash values, of loaded or started components. Commonly, the register values are created in linear order by a hardware-secured operation. Fine-grained diagnosis of components, based on the linear order of verification data and associated measurement logs, is not optimal. We propose a method to use tree-formed verification data to validate a platform. Component measurement values represent leaves, and protected registers represent roots of a hash tree. We describe the basic mechanism of validating a platform using tree-formed measurement logs and root registers and show an logarithmic speed-up for the search of faults. Secure creation of a tree is possible using a limited number of hardware-protected registers and a single protected operation. In this way, the security of tree-formed verification data is maintained.Comment: 15 pages, 11 figures, v3: Reference added, v4: Revised, accepted for publication in Computers and Securit

Compact Hardware Implementation of a SHA-3 Core for Wireless Body Sensor Networks

One of the most important Internet of Things applications is the wireless body sensor network (WBSN), which can provide universal health care, disease prevention, and control. Due to large deployments of small scale smart sensors in WBSNs, security, and privacy guarantees (e.g., security and safety-critical data, sensitive private information) are becoming a challenging issue because these sensor nodes communicate using an open channel, i.e., Internet. We implement data integrity (to resist against malicious tampering) using the secure hash algorithm 3 (SHA-3) when smart sensors in WBSNs communicate with each other using the Internet. Due to the limited resources (i.e., storage, computation, and communication capabilities) of sensors in WBSNs, a lightweight implementation of SHA-3 is needed. To address this challenge, we propose a new implementation of the SHA-3, which has a compact hardware architecture. Our implementation of SHA-3 consists of a reliable logic structure, random access memory, and an enhanced finite state machine. The simulation on a Vitrtex-5 field programmable gate array shows that the proposed implementation is suitable for the WBSN on different applications. We evaluate the sensor area of the proposed SHA-3 implementation and compare it with other recently proposed hardware implementations of SHA-3. In addition, our hardware implementation approach reduces the area by almost 74.7% compared with the recently proposed hardware implementation which has the smallest area

Sähköisen identiteetin toteuttaminen TPM 2.0 -laitteistolla

Most of the financial, healthcare, and governmental services are available on Internet, where traditional identification methods used on face-to-face identification are not possible. Identification with username and password is a mediocre solution and therefore some services require strong authentication. Finland has three approved strong authentication methods: smart cards, bank credentials, and mobile ID. Out of the three authentication methods, only the government issued smart card is available to everyone who police can identify reliably. Bank credentials require identification with an identity document from Finland or other European Economic Area (EEA) country. Mobile ID explicitly require identification with Finnish identity document. The problem with smart cards is the requirement for a reader, slow functioning, and requirement for custom driver. A TPM could function as a replacement for a smart card with accompanying software library. In this thesis, I created a PKCS #11 software library that allows TPM to be used for browser based authentication according to draft specification by Finnish population registry. The keys used for authentication are created, stored and used securely inside the TPM. TPMs are deemed viable replacement for smart cards. The implemented system is faster to use than smart cards and has similar security properties as smart cards have. The created library contains implementations for 30% of all TPM 2.0 functions and could be used as a base for further TPM 2.0 based software.Pankki-, terveys- ja julkiset palvelut ovat suureksi osin saatavilla internetin välityksellä. Tunnistautuminen käyttäjätunnuksella ja salasanalla ei takaa riittävää luotettavuutta, vaan joissain palveluissa on käytettävä vahvaa tunnistautumista. Suomessa on tällä hetkellä käytössä kolme vahvaa tunnistautumisvälinettä: pankkien käyttämät verkkopankkitunnukset, Väestörekisterikeskuksen kansalaisvarmenne ja teleyritysten mobiilivarmenteet. Näistä kolmesta kansalaisvarmenne on ainoa, joka ei vaadi asiakkuutta ja on täten kaikille saatavilla, jotka poliisi voi luotettavasti tunnistaa. Verkkopankkitunnukset vaativat tunnistautumisen suomalaisella tai Euroopan talousalueen (ETA) valtion myöntämällä henkilötodistus. Mobiilivarmenne myönnetään vain henkilölle, joka voidaan tunnistaa suomalaisella henkilötodistuksella. Kansalaisvarmenne on kuitenkin älykortti kaikkine älykortin ongelmineen: sen käyttämiseen tarvitaan erillinen lukija, sen toiminta on hidasta ja se vaatii erillisen laiteajurin. Tämän työn tavoitteena on luoda ratkaisu, jolla älykorttipohjainen tunnistautuminen voidaan toteuttaa tietokoneissa olevan TPM-piirin avulla. Tässä diplomityössä luotiin PKCS #11 -rajapinnan täyttävä ohjelmistokirjasto, joka mahdollistaa TPM-piirin käyttämisen tunnistautumiseen selaimessa Väestörekisterikeskuksen laatiman määritelmän luonnoksen mukaan. Tunnistautumisavaimet luodaan, tallennetaan ja niitä käytetään TPM:ssa, mikä varmistaa avainten luottamuksellisuuden. Älykortin toiminnallisuudet todettiin mahdolliseksi toteuttaa TPM-piirillä. Toteutettu järjestelmä on nopeampi käyttää kuin älykortti ja se takaa älykortteja vastaavan tietoturvatason. Työn tuloksena tehty kirjasto toteuttaa 30 % kaikista TPM 2.0 -ohjelmistorajapinnoista, ja kirjastoa voidaan käyttää osana tulevia TPM 2.0 -ohjelmistoja

Anonymous reputation based reservations in e-commerce (AMNESIC)

Online reservation systems have grown over the last recent years to facilitate the purchase of goods and services. Generally, reservation systems require that customers provide some personal data to make a reservation effective. With this data, service providers can check the consumer history and decide if the user is trustable enough to get the reserve. Although the reputation of a user is a good metric to implement the access control of the system, providing personal and sensitive data to the system presents high privacy risks, since the interests of a user are totally known and tracked by an external entity. In this paper we design an anonymous reservation protocol that uses reputations to profile the users and control their access to the offered services, but at the same time it preserves their privacy not only from the seller but the service provider

On the Exploitation of a High-throughput SHA-256 FPGA Design for HMAC

High-throughput and area-efficient designs of hash functions and corresponding mechanisms for Message Authentication Codes (MACs) are in high demand due to new security protocols that have arisen and call for security services in every transmitted data packet. For instance, IPv6 incorporates the IPSec protocol for secure data transmission. However, the IPSec's performance bottleneck is the HMAC mechanism which is responsible for authenticating the transmitted data. HMAC's performance bottleneck in its turn is the underlying hash function. In this article a high-throughput and small-size SHA-256 hash function FPGA design and the corresponding HMAC FPGA design is presented. Advanced optimization techniques have been deployed leading to a SHA-256 hashing core which performs more than 30% better, compared to the next better design. This improvement is achieved both in terms of throughput as well as in terms of throughput/area cost factor. It is the first reported SHA-256 hashing core that exceeds 11Gbps (after place and route in Xilinx Virtex 6 board)

Secure migration of WebAssembly-based mobile agents between secure enclaves

Cryptography and security protocols are today commonly used to protect data at-rest and in-transit. In contrast, protecting data in-use has seen only limited adoption. Secure data transfer methods employed today rarely provide guarantees regarding the trustworthiness of the software and hardware at the communication endpoints. The field of study that addresses these issues is called Trusted or Confidential Computing and relies on the use of hardware-based techniques. These techniques aim to isolate critical data and its processing from the rest of the system. More specifically, it investigates the use of hardware isolated Secure Execution Environments (SEEs) where applications cannot be tampered with during operation. Over the past few decades, several implementations of SEEs have been introduced, each based on a different hardware architecture. However, lately, the trend is to move towards architecture-independent SEEs. As part of this, Huawei research project is developing a secure enclave framework that enables secure execution and migration of applications (mobile agents), regardless of the underlying architecture. This thesis contributes to the development of the framework by participating in the design and implementation of a secure migration scheme for the mobile agents. The goal is a scheme wherein it is possible to transfer the mobile agent without compromising the security guarantees provided by SEEs. Further, the thesis also provides performance measurements of the migration scheme implemented in a proof of concept of the framework

Virtualized Reconfigurable Resources and Their Secured Provision in an Untrusted Cloud Environment

The cloud computing business grows year after year. To keep up with increasing demand and to offer more services, data center providers are always searching for novel architectures. One of them are FPGAs, reconfigurable hardware with high compute power and energy efficiency. But some clients cannot make use of the remote processing capabilities. Not every involved party is trustworthy and the complex management software has potential security flaws. Hence, clients’ sensitive data or algorithms cannot be sufficiently protected. In this thesis state-of-the-art hardware, cloud and security concepts are analyzed and com- bined. On one side are reconfigurable virtual FPGAs. They are a flexible resource and fulfill the cloud characteristics at the price of security. But on the other side is a strong requirement for said security. To provide it, an immutable controller is embedded enabling a direct, confidential and secure transfer of clients’ configurations. This establishes a trustworthy compute space inside an untrusted cloud environment. Clients can securely transfer their sensitive data and algorithms without involving vulnerable software or a data center provider. This concept is implemented as a prototype. Based on it, necessary changes to current FPGAs are analyzed. To fully enable reconfigurable yet secure hardware in the cloud, a new hybrid architecture is required.Das Geschäft mit dem Cloud Computing wächst Jahr für Jahr. Um mit der steigenden Nachfrage mitzuhalten und neue Angebote zu bieten, sind Betreiber von Rechenzentren immer auf der Suche nach neuen Architekturen. Eine davon sind FPGAs, rekonfigurierbare Hardware mit hoher Rechenleistung und Energieeffizienz. Aber manche Kunden können die ausgelagerten Rechenkapazitäten nicht nutzen. Nicht alle Beteiligten sind vertrauenswürdig und die komplexe Verwaltungssoftware ist anfällig für Sicherheitslücken. Daher können die sensiblen Daten dieser Kunden nicht ausreichend geschützt werden. In dieser Arbeit werden modernste Hardware, Cloud und Sicherheitskonzept analysiert und kombiniert. Auf der einen Seite sind virtuelle FPGAs. Sie sind eine flexible Ressource und haben Cloud Charakteristiken zum Preis der Sicherheit. Aber auf der anderen Seite steht ein hohes Sicherheitsbedürfnis. Um dieses zu bieten ist ein unveränderlicher Controller eingebettet und ermöglicht eine direkte, vertrauliche und sichere Übertragung der Konfigurationen der Kunden. Das etabliert eine vertrauenswürdige Rechenumgebung in einer nicht vertrauenswürdigen Cloud Umgebung. Kunden können sicher ihre sensiblen Daten und Algorithmen übertragen ohne verwundbare Software zu nutzen oder den Betreiber des Rechenzentrums einzubeziehen. Dieses Konzept ist als Prototyp implementiert. Darauf basierend werden nötige Änderungen von modernen FPGAs analysiert. Um in vollem Umfang eine rekonfigurierbare aber dennoch sichere Hardware in der Cloud zu ermöglichen, wird eine neue hybride Architektur benötigt

Swiftmend: Data Synchronization in Open mHealth Applications with Restricted Connectivity

Open mHealth applications often include mobile devices and cloud services with replicated data between components. These replicas need periodical synchronization to remain consistent. However, there are no guarantee of connectivity to networks which do not bill users on the quantity of data usage. This thesis propose Swiftmend, a system with synchronization that minimize the quantity of I/O used on the network. Swiftmend includes two reconciliation algorithms; Rejuvenation and Regrowth. The latter utilizes the efficiency of the Merkle tree data structure to reduce the I/O. Merkle trees can sum up the consistency of replicas into compact fingerprints. While the first reconciliation algorithm, Rejuvenation simply inspects the entire replica to identify consistency. Regrowth is shown to produce less quantity of I/O than Rejuvenation when synchronizing replicas. This is due to the compact fingerprints