A WireGuard Exploration

Internet users require secure means of communication. Virtual Private Networks (VPNs) often serve this purpose, for consumers and businesses. The research aims of this paper were an analysis and implementation of the new VPN protocol WireGuard. The authors explain the cryptographic primitives used, build server and client code implementations of WireGuard peers, and present the benefits and drawbacks of this new technology. The outcome was a functional WireGuard client and server implementation, capable of tunneling all Internet traffic through a cloud-based virtual private server (VPS), with minimal manual configuration necessary from the end user. The code is publicly available

A Discussion of Internal Communication Procedure of Transport Layer Security Protocol on Telecommunication Networks

The research paper written by us discusses the review of internal communication procedure of Transport Layer Security protocol on telecommunication networks. In this research paper we discuss the security measures and security techniques employed by Transport Layer Security protocol for the provision of data privacy, confidentiality and authentication on telecommunication networks to the network users. The telecommunication networks include both the wired and wireless communication networks mostly including computer communication networks. The connection establishment for connecting client side and server side used by Transport Layer Security protocol is discussed in this research paper in order to facilitate the understanding of internal connection establishment and internal connection management procedure between client side and server side of telecommunication network. We have focused on Cipher Suit and Security Services provided by Transport Layer Security protocol in detail in order to high light key features of connection establishment in Transport Layer Security protocol. The discussion in the research paper will be useful for extension of Transport Layer Security protocol’s usability and implementations by researchers

Blind Password Registration for Two-Server Password Authenticated Key Exchange and Secret Sharing Protocols

Many organisations enforce policies on the length and formation of passwords to encourage selection of strong passwords and protect their multi-user systems. For Two-Server Password Authenticated Key Exchange (2PAKE) and Two-Server Password Authenticated Secret Sharing (2PASS) protocols, where the password chosen by the client is secretly shared between the two servers, the initial remote registration of policy-compliant passwords represents a major problem because none of the servers is supposed to know the password in clear. We solve this problem by introducing Two-Server Blind Password Registration (2BPR) protocols that can be executed between a client and the two servers as part of the remote registration procedure. 2BPR protocols guarantee that secret shares sent to the servers belong to a password that matches their combined password policy and that the plain password remains hidden from any attacker that is in control of at most one server. We propose a security model for 2BPR protocols capturing the requirements of policy compliance for client passwords and their blindness against the servers. Our model extends the adversarial setting of 2PAKE/2PASS protocols to the registration phase and hence closes the gap in the formal treatment of such protocols. We construct an efficient 2BPR protocol for ASCII-based password policies, prove its security in the standard model, give a proof of concept implementation, and discuss its performance

Towards Forward Secure Internet Traffic

Forward Secrecy (FS) is a security property in key-exchange algorithms which guarantees that a compromise in the secrecy of a long-term private-key does not compromise the secrecy of past session keys. With a growing awareness of long-term mass surveillance programs by governments and others, FS has become widely regarded as a highly desirable property. This is particularly true in the TLS protocol, which is used to secure Internet communication. In this paper, we investigate FS in pre-TLS 1.3 protocols, which do not mandate FS, but still widely used today. We conduct an empirical analysis of over 10 million TLS servers from three different datasets using a novel heuristic approach. Using a modern TLS client handshake algorithms, our results show 5.37% of top domains, 7.51% of random domains, and 26.16% of random IPs do not select FS key-exchange algorithms. Surprisingly, 39.20% of the top domains, 24.40% of the random domains, and 14.46% of the random IPs that do not select FS, do support FS. In light of this analysis, we discuss possible paths toward forward secure Internet traffic. As an improvement of the current state, we propose a new client-side mechanism that we call "Best Effort Forward Secrecy" (BEFS), and an extension of it that we call "Best Effort Forward Secrecy and Authenticated Encryption" (BESAFE), which aims to guide (force) misconfigured servers to FS using a best effort approach. Finally, within our analysis, we introduce a novel adversarial model that we call "discriminatory" adversary, which is applicable to the TLS protocol

Towards Modeling Privacy in WiFi Fingerprinting Indoor Localization and its Application

In this paper, we study privacy models for privacy-preserving WiFi fingerprint based indoor local- ization (PPIL) schemes. We show that many existing models are insufficient and make unrealistic assumptions regarding adversaries’ power. To cover the state-of-the-art practical attacks, we propose the first formal security model which formulates the security goals of both client-side and server-side privacy beyond the curious-but-honest setting. In particular, our model considers various malicious behaviors such as exposing secrets of principles, choosing malicious WiFi fingerprints in location queries, and specifying the location area of a target client. Furthermore, we formulate the client-side privacy in an indistinguishability manner where an adversary is required to distinguish a client’s real location from a random one. The server-side privacy requires that adversaries cannot generate a fab- ricate database which provides a similar function to the real database of the server. In particular, we formally define the similarity between databases with a ball approach that has not been formalized before. We show the validity and applicability of our model by applying it to analyze the security of an existing PPIL protocol. We also design experiments to test the server-privacy in the presence of database leakage, based on a candidate server-privacy attack.Peer reviewe

Frodo: Take off the ring! Practical, quantum-secure key exchange from LWE

Lattice-based cryptography offers some of the most attractive primitives believed to be resistant to quantum computers. Following increasing interest from both companies and government agencies in building quantum computers, a number of works have proposed instantiations of practical post-quantum key exchange protocols based on hard problems in ideal lattices, mainly based on the Ring Learning With Errors (R-LWE) problem. While ideal lattices facilitate major efficiency and storage benefits over their nonideal counterparts, the additional ring structure that enables these advantages also raises concerns about the assumed difficulty of the underlying problems. Thus, a question of significant interest to cryptographers, and especially to those currently placing bets on primitives that will withstand quantum adversaries, is how much of an advantage the additional ring structure actually gives in practice. Despite conventional wisdom that generic lattices might be too slow and unwieldy, we demonstrate that LWE-based key exchange is quite practical: our constant time implementation requires around 1.3ms computation time for each party; compared to the recent NewHope R-LWE scheme, communication sizes increase by a factor of 4.7×, but remain under 12 KiB in each direction. Our protocol is competitive when used for serving web pages over TLS; when partnered with ECDSA signatures, latencies increase by less than a factor of 1.6×, and (even under heavy load) server throughput only decreases by factors of 1.5× and 1.2× when serving typical 1 KiB and 100 KiB pages, respectively. To achieve these practical results, our protocol takes advantage of several innovations. These include techniques to optimize communication bandwidth, dynamic generation of public parameters (which also offers additional security against backdoors), carefully chosen error distributions, and tight security parameters

Content delivery over TLS: a cryptographic analysis of keyless SSL

The Transport Layer Security (TLS) protocol is designed to allow two parties, a client and a server, to communicate securely over an insecure network. However, when TLS connections are proxied through an intermediate middlebox, like a Content Delivery Network (CDN), the standard endto- end security guarantees of the protocol no longer apply. In this paper, we investigate the security guarantees provided by Keyless SSL, a CDN architecture currently deployed by CloudFlare that composes two TLS 1.2 handshakes to obtain a proxied TLS connection. We demonstrate new attacks that show that Keyless SSL does not meet its intended security goals. These attacks have been reported to CloudFlare and we are in the process of discussing fixes. We argue that proxied TLS handshakes require a new, stronger, 3-party security definition. We present 3(S)ACCEsecurity, a generalization of the 2-party ACCE security definition that has been used in several previous proofs for TLS. We modify Keyless SSL and prove that our modifications guarantee 3(S)ACCE-security, assuming ACCE-security for the individual TLS 1.2 connections. We also propose a new design for Keyless TLS 1.3 and prove that it achieves 3(S)ACCEsecurity, assuming that the TLS 1.3 handshake implements an authenticated 2-party key exchange. Notably, we show that secure proxying in Keyless TLS 1.3 is computationally lighter and requires simpler assumptions on the certificate infrastructure than our proposed fix for Keyless SSL. Our results indicate that proxied TLS architectures, as currently used by a number of CDNs, may be vulnerable to subtle attacks and deserve close attention

Protocol state fuzzing of TLS implementations

We describe a largely automated and systematic analysis of TLS implementations by what we call ‘protocol state fuzzing’: we use state machine learning to infer state ma-chines from protocol implementations, using only black-box testing, and then inspect the inferred state machines to look for spurious behaviour which might be an indica-tion of flaws in the program logic. For detecting the pres-ence of spurious behaviour the approach is almost fully automatic: we automatically obtain state machines and any spurious behaviour is then trivial to see. Detecting whether the spurious behaviour introduces exploitable security weaknesses does require manual investigation. Still, we take the point of view that any spurious func-tionality in a security protocol implementation is danger-ous and should be removed. We analysed both server- and client-side implemen-tations with a test harness that supports several key ex-change algorithms and the option of client certificate au-thentication. We show that this approach can catch an interesting class of implementation flaws that is appar-ently common in security protocol implementations: in three of the TLS implementations analysed new security flaws were found (in GnuTLS, the Java Secure Socket Extension, and OpenSSL). This shows that protocol state fuzzing is a useful technique to systematically analyse security protocol implementations. As our analysis of different TLS implementations resulted in different and unique state machines for each one, the technique can also be used for fingerprinting TLS implementations.

Post-Quantum Key Exchange for the Internet and the Open Quantum Safe Project

Designing public key cryptosystems that resist attacks by quantum computers is an important area of current cryptographic research and standardization. To retain confidentiality of today\u27s communications against future quantum computers, applications and protocols must begin exploring the use of quantum-resistant key exchange and encryption. In this paper, we explore post-quantum cryptography in general and key exchange specifically. We review two protocols for quantum-resistant key exchange based on lattice problems: BCNS15, based on the ring learning with errors problem, and Frodo, based on the learning with errors problem. We discuss their security and performance characteristics, both on their own and in the context of the Transport Layer Security (TLS) protocol. We introduce the Open Quantum Safe project, an open-source software project for prototyping quantum-resistant cryptography, which includes liboqs, a C library of quantum-resistant algorithms, and our integrations of liboqs into popular open-source applications and protocols, including the widely used OpenSSL library