skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Break-Glass Encryption
“Break-glass” is a term used in IT healthcare systems to denote an emergency access to private information without having the credentials to do so. In this paper we introduce the concept of break-glass encryption for cloud storage, where the security of the ciphertexts – stored on a cloud – can be violated exactly once, for emergency circumstances, in a way that is detectable and without relying on a trusted party. Detectability is the crucial property here: if a cloud breaks glass without permission from the legitimate user, the latter should detect it and have a proof of such violation. However, if the break-glass procedure is invoked by the legitimate user, then semantic security must still hold and the cloud will learn nothing. Distinguishing that a break-glass is requested by the legitimate party is also challenging in absence of secrets. In this paper, we provide a formalization of break-glass encryption and a secure instantiation using hardware tokens. Our construction aims to be a feasibility result and is admittedly impractical. Whether hardware tokens are necessary to achieve this security notion and whether more practical solutions can be devised are interesting open questions.  more » « less
Award ID(s):
1718074
PAR ID:
10098718
Author(s) / Creator(s):
Date Published:
Journal Name:
Public Key Encryption Conference
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Trigger-Action platforms are web-based systems that enable users to create automation rules by stitching together online services representing digital and physical resources using OAuth tokens. Unfortunately, these platforms introduce a longrange large-scale security risk: If they are compromised, an attacker can misuse the OAuth tokens belonging to a large number of users to arbitrarily manipulate their devices and data. We introduce Decentralized Action Integrity, a security principle that prevents an untrusted trigger-action platform from misusing compromised OAuth tokens in ways that are inconsistent with any given user’s set of trigger-action rules. We present the design and evaluation of Decentralized Trigger-Action Platform (DTAP), a trigger-action platform that implements this principle by overcoming practical challenges. DTAP splits currently monolithic platform designs into an untrusted cloud service, and a set of user clients (each user only trusts their client). Our design introduces the concept of Transfer Tokens (XTokens) to practically use finegrained rule-specific tokens without increasing the number of OAuth permission prompts compared to current platforms. Our evaluation indicates that DTAP poses negligible overhead: it adds less than 15ms of latency to rule execution time, and reduces throughput by 2.5%. 
    more » « less
  2. Edge Computing is a new computing paradigm where applications operate at the network edge, providing low-latency services with augmented user and data privacy. A desirable goal for edge computing is pervasiveness, that is, enabling any capable and authorized entity at the edge to provide desired edge services--pervasive edge computing (PEC). However, efficient access control of users receiving services and edge servers handling user data, without sacrificing performance is a challenge. Current solutions, based on "always-on" authentication servers in the cloud, negate the latency benefits of services at the edge and also do not preserve user and data privacy. In this paper, we present APECS, an advanced access control framework for PEC, which allows legitimate users to utilize any available edge services without need for communication beyond the network edge. The APECS framework leverages multi-authority attribute-based encryption to create a federated authority, which delegates the authentication and authorization tasks to semi-trusted edge servers, thus eliminating the need for an "always-on" authentication server in the cloud. Additionally, APECS prevents access to encrypted content by unauthorized edge servers. We analyze and prove the security of APECS in the Universal Composability framework and provide experimental results on the GENI testbed to demonstrate the scalability and effectiveness of APECS. 
    more » « less
  3. Because FPGAs outperform traditional processing cores like CPUs and GPUs in terms of performance per watt and flexibility, they are being used more and more in cloud and data center applications. There are growing worries about the security risks posed by multi-tenant sharing as the demand for hardware acceleration increases and gradually gives way to FPGA multi-tenancy in the cloud. The confidentiality, integrity, and availability of FPGA-accelerated applications may be compromised if space-shared FPGAs are made available to many cloud tenants. We propose a root of trust-based trusted execution mechanism called TrustToken to prevent harmful software-level attackers from getting unauthorized access and jeopardizing security. With safe key creation and truly random sources, TrustToken creates a security block that serves as the foundation of trust-based IP security. By offering crucial security characteristics, such as secure, isolated execution and trusted user interaction, TrustToken only permits trustworthy connection between the non-trusted third-party IP and the rest of the SoC environment. The suggested approach does this by connecting the third-party IP interface to the TrustToken Controller and running run-time checks on the correctness of the IP authorization(Token) signals. With an emphasis on software-based assaults targeting unauthorized access and information leakage, we offer a noble hardware/software architecture for trusted execution in FPGA-accelerated clouds and data centers. 
    more » « less
  4. Logic encryption is a powerful hardware protection technique that uses extra key inputs to lock a circuit from piracy or unauthorized use. The recent discovery of the SAT-based attack with Distinguishing Input Pattern (DIP) generation has rendered all traditional logic encryptions vulnerable, and thus the creation of new encryption methods. However, a critical question for any new encryption method is whether security against the DIP-generation attack means security against all other attacks. In this paper, a new high-level SAT-based attack called SigAttack has been discovered and thoroughly investigated. It is based on extracting a key-revealing signature in the encryption. A majority of all known SAT-resilient encryptions are shown to be vulnerable to SigAttack. By formulating the condition under which SigAttack is effective, the paper also provides guidance for the future logic encryption design. 
    more » « less
  5. The Internet of Things (IoT) harbors a large number of resource-limited devices (e.g., sensors) that continuously generate and offload sensitive information (e.g., financial, health, personal). It is imperative the ensure the trustworthiness of this data with efficient cryptographic mechanisms. Digital signatures can offer scalable authentication with public verifiability and nonrepudiation. However, the state-of-the-art digital signatures do not offer the desired efficiency and are not scalable for the connected resource-limited IoT devices. This is without considering long term security features such as post-quantum security and forward security. In this paper, we summarize the main challenges to an energy-aware and efficient signature scheme. Then, we propose new scheme design improvements that uniquely embed different emerging technologies such as Mutli-Party Computation (MPC) and secure enclaves (e.g., Intel SGX) in order to secret-share confidential keys of low-end IoT devices across multiple cloud servers. We also envision building signature schemes with Fully Homomorphic Encryption (FHE) to enable verifiers to compute expensive commitments under encryption. We provide evaluation metrics that showcase the feasibility and efficiency of our designs for potential deployment on embedded devices in IoT. 
    more » « less