John G. Brainard

Bio: John G. Brainard is an academic researcher from EMC Corporation. The author has contributed to research in topics: Authentication & Security token. The author has an hindex of 14, co-authored 43 publications receiving 2208 citations. Previous affiliations of John G. Brainard include RSA.

Fourth-factor authentication: somebody you know

Abstract: User authentication in computing systems traditionally depends on three factors: something you have (e.g., a hardware token), something you are (e.g., a fingerprint), and something you know (e.g., a password). In this paper, we explore a fourth factor, the social network of the user, that is, somebody you know.Human authentication through mutual acquaintance is an age-old practice. In the arena of computer security, it plays roles in privilege delegation, peer-level certification, help-desk assistance, and reputation networks. As a direct means of logical authentication, though, the reliance of human being on another has little supporting scientific literature or practice.In this paper, we explore the notion of vouching, that is, peer-level, human-intermediated authentication for access control. We explore its use in emergency authentication, when primary authenticators like passwords or hardware tokens become unavailable. We describe a practical, prototype vouching system based on SecurID, a popular hardware authentication token. We address traditional, cryptographic security requirements, but also consider questions of social engineering and user behavior.

Method and apparatus for performing enhanced time-based authentication

Abstract: A time-based method for generating an authentication code associated with an entity uses an authentication code generated from a secret, a dynamic, time-varying variable, and the number of previous authentication code generations within the particular time interval. Other information such as a personal identification number (PIN) and a verifier identifier can also be combined into the authentication code.

System and method for authentication seed distribution

Abstract: In one embodiment of a user authentication system and method according to the invention, a device shares a secret, referred to as a master seed, with a server. The device and the server both derive one or more secrets, referred to as verifier seeds, from the master seed, using a key derivation function. The server shares a verifier seed with one or more verifiers. The device, or an entity using the device, can authenticate with one of the verifiers using the appropriate verifier seed. In this way, the device and the verifier can share a secret, the verifier seed for that verifier, without that verifier knowing the master seed, or any other verifier seeds. Thus, the device need only store the one master seed, have access to the information necessary to correctly derive the appropriate seed, and have seed derivation capability. A verifier cannot compromise the master seed, because the verifier does not have access to the master seed.

Soft blocking: flexible blocker tags on the cheap

Abstract: A "blocker" tag is a privacy-enhancing radio-frequency identification (RFID) tag. It operates by interfering with the protocol in which a reader communicates individually with other RFID tags. While inexpensive to manufacture in quantity, blockers are nonetheless special-purpose devices, and thus introduce level of complexity that may pose an obstacle to their deployment.We propose a variant on the blocker concept that we call soft blocking. This involves software (or firmware) modules that offer a different balance of characteristics than ordinary blockers. Soft blocking offers somewhat weaker privacy enforcement that is essentially voluntary or internally auditable (much like P3P). It has the significant advantage, however, of relying on standard (or very slightly modified) RFID tags. Additionally, soft blocking offers the possibility of flexible privacy policies in which partial or scrubbed data is revealed about "private" tags, in lieu of the all-or-nothing policy enforced by a blocker.We show, moreover, how the correct functioning of a soft-blocker system may be rendered externally auditable with minor modifications to the basic tag-reading protocol. We also briefly discuss the special, attractive approach of unblocking, a soft-blocking variant that permits an "opt-in" approach to consumer privacy.

RFID security and privacy: a research survey

Abstract: This paper surveys recent technical research on the problems of privacy and security for radio frequency identification (RFID). RFID tags are small, wireless devices that help identify objects and people. Thanks to dropping cost, they are likely to proliferate into the billions in the next several years-and eventually into the trillions. RFID tags track objects in supply chains, and are working their way into the pockets, belongings, and even the bodies of consumers. This survey examines approaches proposed by scientists for privacy protection and integrity assurance in RFID systems, and treats the social and technical context of their work. While geared toward the nonspecialist, the survey may also serve as a reference for specialist readers.

A taxonomy of DDoS attack and DDoS defense mechanisms

Abstract: Distributed denial-of-service (DDoS) is a rapidly growing problem. The multitude and variety of both the attacks and the defense approaches is overwhelming. This paper presents two taxonomies for classifying attacks and defenses, and thus provides researchers with a better understanding of the problem and the current solution space. The attack classification criteria was selected to highlight commonalities and important features of attack strategies, that define challenges and dictate the design of countermeasures. The defense taxonomy classifies the body of existing DDoS defenses based on their design decisions; it then shows how these decisions dictate the advantages and deficiencies of proposed solutions.

The Bitcoin Backbone Protocol: Analysis and Applications

Abstract: Bitcoin is the first and most popular decentralized cryptocurrency to date. In this work, we extract and analyze the core of the Bitcoin protocol, which we term the Bitcoin backbone, and prove two of its fundamental properties which we call common prefix and chain quality in the static setting where the number of players remains fixed. Our proofs hinge on appropriate and novel assumptions on the “hashing power” of the adversary relative to network synchronicity; we show our results to be tight under high synchronization.

The Quest to Replace Passwords: A Framework for Comparative Evaluation of Web Authentication Schemes

Abstract: We evaluate two decades of proposals to replace text passwords for general-purpose user authentication on the web using a broad set of twenty-five usability, deployability and security benefits that an ideal scheme might provide. The scope of proposals we survey is also extensive, including password management software, federated login protocols, graphical password schemes, cognitive authentication schemes, one-time passwords, hardware tokens, phone-aided schemes and biometrics. Our comprehensive approach leads to key insights about the difficulty of replacing passwords. Not only does no known scheme come close to providing all desired benefits: none even retains the full set of benefits that legacy passwords already provide. In particular, there is a wide range from schemes offering minor security benefits beyond legacy passwords, to those offering significant security benefits in return for being more costly to deploy or more difficult to use. We conclude that many academic proposals have failed to gain traction because researchers rarely consider a sufficiently wide range of real-world constraints. Beyond our analysis of current schemes, our framework provides an evaluation methodology and benchmark for future web authentication proposals.

Hashcash - A Denial of Service Counter-Measure

Abstract: Hashcash was originally proposed as a mechanism to throttle systematic abuse of un-metered internet resources such as email, and anonymous remailers in May 1997. Five years on, this paper captures in one place the various applications, improvements suggested and related subsequent publications, and describes initial experience from experiments using hashcash. The hashcash CPU cost-function computes a token which can be used as a proof-of-work. Interactive and noninteractive variants of cost-functions can be constructed which can be used in situations where the server can issue a challenge (connection oriented interactive protocol), and where it can not (where the communication is store–and– forward, or packet oriented) respectively.