Network level surveillance, censorship, and various man-in-the-middle attacks target only specific types of network traffic (e.g., HTTP, HTTPS, VoIP, or Email). Therefore packets of these types will likely receive ”special” treatment by a transit network or a man-in-the-middle attacker. A transit ISP or an attacker may pass the targeted traffic through special software or equipment to gather da...

Strong notions of security for unconditionally secure digital signature schemes (USDS) were recently proposed where security is defined based on notions of security in computationally–secure digital signatures. The traditional area of unconditionally secure authentication, however, is that of “authentication codes” (A–codes). Relations between primitives is central to cryptographic research. To...

As traditional oblivious transfer protocols are treated as cryptographic primitives in most cases, they are usually executed without the consideration of possible attacks, e.g., impersonation, replaying, and man-in-the-middle attacks. Therefore, when these protocols are applied in certain applications, such as mental poker game playing and fairly contracts signing, some extra mechanisms must be...

The security community seems to be thoroughly familiar with man-in-the-middle attacks. However, the common perception of this type of attack is outdated. It originates from when network connections were fixed, not mobile, before 24/7 connectivity became ubiquitous. The common perception of this attack stems from an era before the vulnerability of the protocol’s context was realised. Thanks to r...

Non-malleability is an important security property of commitment schemes. The property means security against the man-in-the-middle attack, and it is defined and proved in the simulation paradigm using the corresponding simulator. Many known non-malleable commitment schemes have the common drawback that their corresponding simulators do not work in a straight-line manner, requires rewinding of ...

Secret-key authentication protocols have recently received a considerable amount of attention, and a long line of research has been devoted to devising efficient protocols with security based on the hardness of the learning-parity with noise (LPN) problem, with the goal of achieving low communication and round complexities, as well as highest possible security guarantees. In this paper, we cons...

Secure initial pairing of electronic gadgets is a challenging problem, especially considering lack of any common security infrastructure. The main security issue is the threat of so-called Man-in-the-Middle (MiTM) attacks, whereby an attacker inserts itself into the pairing protocol by impersonating one of the legitimate parties. A number of interesting techniques have been proposed, all of whi...

Exponential growth of the volume of Bluetooth-enabled devices indicates that it has become a popular way of wireless interconnections for exchanging information. The main goal of this paper is to analyze the most critical Bluetooth attacks in real scenarios. In order to find out the major vulnerabilities in modern Bluetooth-enabled mobile devices several attacks have performed successfully such...

BankID is a PKI-substitute widely deployed by Norwegian banks to provide digital signatures and identification on the internet. We have performed a reverse-engineering of part of the BankID system and analysed the security protocols and the implementation of certain cryptographic primitives. We have found cryptographic weaknesses that may indicate security problems, protocol flaws facilitating ...

Recently, Shim proposed a tripartite authenticated key agreement protocol from Weil pairing to overcome the security flaw in Joux’s protocol. Later, Shim also proposed an ID-based authenticated key agreement protocol which is an improvement of Smart’s protocol in order to provide the forward secrecy. In this paper, we show that these two protocols are insecure against the key-compromise imperso...