arXiv subjects

Adrian Perrig

Publications and source records attributed to Adrian Perrig.

48 records · Page 3Linked to original sources

arXiv2016

Source Accountability with Domain-brokered Privacy

In an ideal network, every packet would be attributable to its sender, while host identities and transmitted content would remain private. Designing such a network is challenging because source accountability and communication privacy are typically viewed as conflicting properties. In this paper, we propose an architecture that guarantees source accountability and privacy-preserving communication by enlisting ISPs as accountability agents and privacy brokers. While ISPs can link every packet in their network to their customers, customer identity remains unknown to the rest of the Internet. In our architecture, network communication is based on Ephemeral Identifiers (EphIDs)---cryptographic tokens that can be linked to a source only by the source's ISP. We demonstrate that EphIDs can be generated and processed efficiently, and we analyze the practical considerations for deployment.

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arXiv2016

RITM: Revocation in the Middle

Although TLS is used on a daily basis by many critical applications, the public-key infrastructure that it relies on still lacks an adequate revocation mechanism. An ideal revocation mechanism should be inexpensive, efficient, secure, and privacy-preserving. Moreover, rising trends in pervasive encryption pose new scalability challenges that a modern revocation system should address. In this paper, we investigate how network nodes can deliver certificate-validity information to clients. We present RITM, a framework in which middleboxes (as opposed to clients, servers, or certification authorities) store revocation-related data. RITM provides a secure revocation-checking mechanism that preserves user privacy. We also propose to take advantage of content-delivery networks (CDNs) and argue that they would constitute a fast and cost-effective way to disseminate revocations. Additionally, RITM keeps certification authorities accountable for the revocations that they have issued, and it minimizes overhead at clients and servers, as they have to neither store nor download any messages. We also describe feasible deployment models and present an evaluation of RITM to demonstrate its feasibility and benefits in a real-world deployment.

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arXiv2016

SDNsec: Forwarding Accountability for the SDN Data Plane

SDN promises to make networks more flexible, programmable, and easier to manage. Inherent security problems in SDN today, however, pose a threat to the promised benefits. First, the network operator lacks tools to proactively ensure that policies will be followed or to reactively inspect the behavior of the network. Second, the distributed nature of state updates at the data plane leads to inconsistent network behavior during reconfigurations. Third, the large flow space makes the data plane susceptible to state exhaustion attacks. This paper presents SDNsec, an SDN security extension that provides forwarding accountability for the SDN data plane. Forwarding rules are encoded in the packet, ensuring consistent network behavior during reconfigurations and limiting state exhaustion attacks due to table lookups. Symmetric-key cryptography is used to protect the integrity of the forwarding rules and enforce them at each switch. A complementary path validation mechanism allows the controller to reactively examine the actual path taken by the packets. Furthermore, we present mechanisms for secure link-failure recovery and multicast/broadcast forwarding.

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arXiv2016

FAIR: Forwarding Accountability for Internet Reputability

This paper presents FAIR, a forwarding accountability mechanism that incentivizes ISPs to apply stricter security policies to their customers. The Autonomous System (AS) of the receiver specifies a traffic profile that the sender AS must adhere to. Transit ASes on the path mark packets. In case of traffic profile violations, the marked packets are used as a proof of misbehavior. FAIR introduces low bandwidth overhead and requires no per-packet and no per-flow state for forwarding. We describe integration with IP and demonstrate a software switch running on commodity hardware that can switch packets at a line rate of 120 Gbps, and can forward 140M minimum-sized packets per second, limited by the hardware I/O subsystem. Moreover, this paper proposes a "suspicious bit" for packet headers - an application that builds on top of FAIR's proofs of misbehavior and flags packets to warn other entities in the network.

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arXiv2016

HORNET: High-speed Onion Routing at the Network Layer

We present HORNET, a system that enables high-speed end-to-end anonymous channels by leveraging next generation network architectures. HORNET is designed as a low-latency onion routing system that operates at the network layer thus enabling a wide range of applications. Our system uses only symmetric cryptography for data forwarding yet requires no per-flow state on intermediate nodes. This design enables HORNET nodes to process anonymous traffic at over 93 Gb/s. HORNET can also scale as required, adding minimal processing overhead per additional anonymous channel. We discuss design and implementation details, as well as a performance and security evaluation.

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arXiv2016

PKI Safety Net (PKISN): Addressing the Too-Big-to-Be-Revoked Problem of the TLS Ecosystem

In a public-key infrastructure (PKI), clients must have an efficient and secure way to determine whether a certificate was revoked (by an entity considered as legitimate to do so), while preserving user privacy. A few certification authorities (CAs) are currently responsible for the issuance of the large majority of TLS certificates. These certificates are considered valid only if the certificate of the issuing CA is also valid. The certificates of these important CAs are effectively too big to be revoked, as revoking them would result in massive collateral damage. To solve this problem, we redesign the current revocation system with a novel approach that we call PKI Safety Net (PKISN), which uses publicly accessible logs to store certificates (in the spirit of Certificate Transparency) and revocations. The proposed system extends existing mechanisms, which enables simple deployment. Moreover, we present a complete implementation and evaluation of our scheme.

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arXiv2016

SIBRA: Scalable Internet Bandwidth Reservation Architecture

This paper proposes a Scalable Internet Bandwidth Reservation Architecture (SIBRA) as a new approach against DDoS attacks, which, until now, continue to be a menace on today's Internet. SIBRA provides scalable inter-domain resource allocations and botnet-size independence, an important property to realize why previous defense approaches are insufficient. Botnet-size independence enables two end hosts to set up communication regardless of the size of distributed botnets in any Autonomous System in the Internet. SIBRA thus ends the arms race between DDoS attackers and defenders. Furthermore, SIBRA is based on purely stateless operations for reservation renewal, flow monitoring, and policing, resulting in highly efficient router operation, which is demonstrated with a full implementation. Finally, SIBRA supports Dynamic Interdomain Leased Lines (DILLs), offering new business opportunities for ISPs.

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arXiv2015

Efficient Gossip Protocols for Verifying the Consistency of Certificate Logs

The level of trust accorded to certification authorities has been decreasing over the last few years as several cases of misbehavior and compromise have been observed. Log-based approaches, such as Certificate Transparency, ensure that fraudulent TLS certificates become publicly visible. However, a key element that log-based approaches still lack is a way for clients to verify that the log behaves in a consistent and honest manner. This task is challenging due to privacy, efficiency, and deployability reasons. In this paper, we propose the first (to the best of our knowledge) gossip protocols that enable the detection of log inconsistencies. We analyze these protocols and present the results of a simulation based on real Internet traffic traces. We also give a deployment plan, discuss technical issues, and present an implementation.

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arXiv2015

A Practical System for Guaranteed Access in the Presence of DDoS Attacks and Flash Crowds

With the growing incidents of flash crowds and sophisticated DDoS attacks mimicking benign traffic, it becomes challenging to protect Internet-based services solely by differentiating attack traffic from legitimate traffic. While fair-sharing schemes are commonly suggested as a defense when differentiation is difficult, they alone may suffer from highly variable or even unbounded waiting times. We propose RainCheck Filter (RCF), a lightweight primitive that guarantees bounded waiting time for clients despite server flooding without keeping per-client state on the server. RCF achieves strong waiting time guarantees by prioritizing clients based on how long the clients have waited-as if the server maintained a queue in which the clients lined up waiting for service. To avoid keeping state for every incoming client request, the server sends to the client a raincheck, a timestamped cryptographic token that not only informs the client to retry later but also serves as a proof of the client's priority level within the virtual queue. We prove that every client complying with RCF can access the server in bounded time, even under a flash crowd incident or a DDoS attack. Our large-scale simulations confirm that RCF provides a small and predictable maximum waiting time while existing schemes cannot. To demonstrate its deployability, we implement RCF as a Python module such that web developers can protect a critical server resource by adding only three lines of code.

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arXiv2015

Bootstrapping Real-world Deployment of Future Internet Architectures

The past decade has seen many proposals for future Internet architectures. Most of these proposals require substantial changes to the current networking infrastructure and end-user devices, resulting in a failure to move from theory to real-world deployment. This paper describes one possible strategy for bootstrapping the initial deployment of future Internet architectures by focusing on providing high availability as an incentive for early adopters. Through large-scale simulation and real-world implementation, we show that with only a small number of adopting ISPs, customers can obtain high availability guarantees. We discuss design, implementation, and evaluation of an availability device that allows customers to bridge into the future Internet architecture without modifications to their existing infrastructure.

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arXiv2015

SCION Five Years Later: Revisiting Scalability, Control, and Isolation on Next-Generation Networks

The SCION (Scalability, Control, and Isolation on Next-generation Networks) inter-domain network architecture was proposed to address the availability, scalability, and security shortcomings of the current Internet. This paper presents a retrospective of the SCION goals and design decisions, its attacker model and limitations, and research highlights of work conducted in the 5 years following SCION's initial publication.

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arXiv2015

Designing a Global Authentication Infrastructure

We address the problem of scaling authentication for naming, routing, and end-entity certification to a global environment in which authentication policies and users' sets of trust roots vary widely. The current mechanisms for authenticating names (DNSSEC), routes (BGPSEC), and end-entity certificates (TLS) do not support a coexistence of authentication policies, affect the entire Internet when compromised, cannot update trust root information efficiently, and do not provide users with the ability to make flexible trust decisions. We propose a Scalable Authentication Infrastructure for Next-generation Trust (SAINT), which partitions the Internet into groups with common, local trust roots, and isolates the effects of a compromised trust root. SAINT requires groups with direct routing connections to cross-sign each other for authentication purposes, allowing diverse authentication policies while keeping all entities globally verifiable. SAINT makes trust root management a central part of the network architecture, enabling trust root updates within seconds and allowing users to make flexible trust decisions. SAINT operates without a significant performance penalty and can be deployed alongside existing infrastructures.

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