An attacker can obtain a valid TLS certificate for a domain
by hijacking communication between a certificate authority
(CA) and a victim domain. Performing domain validation
from multiple vantage points can defend against these
attacks. We explore the design space of multi-vantage-point
domain validation to achieve (1) security via sufficiently
diverse vantage points, (2) performance by ensuring low
latency and overhead in certificate issuance, (3) manageability
by complying with CA/Browser forum requirements, and
requiring minimal changes to CA operations, and (4) a
low benign failure rate for legitimate requests. Our open-
source implementation was deployed by the Let’s Encrypt
CA in February 2020, and has since secured the issuance
of more than half a billion certificates during the first year
of its deployment. Using real-world operational data from
Let’s Encrypt, we show that our approach has negligible
latency and communication overhead, and a benign failure
rate comparable to conventional designs with one vantage
point. Finally, we evaluate the security improvements using a
combination of ethically conducted real-world BGP hijacks,
Internet-scale traceroute experiments, and a novel BGP
simulation framework. We show that multi-vantage-point
domain validation can thwart the vast majority of BGP attacks.
Our work motivates the deployment of multi-vantage-point
domain validation across the CA ecosystem to strengthen
TLS certificate issuance and user privacy.
more »
« less
Experiences Deploying Multi-Vantage-Point Domain Validation at Let’s Encrypt
An attacker can obtain a valid TLS certificate for a domain by hijacking communication between a certificate authority (CA) and a victim domain. Performing domain validation from multiple vantage points can defend against these attacks. We explore the design space of multi-vantage-point domain validation to achieve (1) security via sufficiently diverse vantage points, (2) performance by ensuring low latency and overhead in certificate issuance, (3) manageability by complying with CA/Browser forum requirements, and requiring minimal changes to CA operations, and (4) a low benign failure rate for legitimate requests. Our opensource implementation was deployed by the Let's Encrypt CA in February 2020, and has since secured the issuance of more than half a billion certificates during the first year of its deployment. Using real-world operational data from Let's Encrypt, we show that our approach has negligible latency and communication overhead, and a benign failure rate comparable to conventional designs with one vantage point. Finally, we evaluate the security improvements using a combination of ethically conducted real-world BGP hijacks, Internet-scale traceroute experiments, and a novel BGP simulation framework. We show that multi-vantage-point domain validation can thwart the vast majority of BGP attacks. Our work motivates the deployment of multi-vantage-point domain validation across the CA ecosystem to strengthen TLS certificate issuance and user privacy.
more »
« less
- NSF-PAR ID:
- 10299416
- Date Published:
- Journal Name:
- Proceedings of the 30th USENIX Security Symposium
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
null (Ed.)Let's Encrypt is a free, open, and automated HTTPS certificate authority (CA) created to advance HTTPS adoption to the entire Web. Since its launch in late 2015, Let's Encrypt has grown to become the world's largest HTTPS CA, accounting for more currently valid certificates than all other browser-trusted CAs combined. By January 2019, it had issued over 538 million certificates for 223 million domain names. We describe how we built Let's Encrypt, including the architecture of the CA software system (Boulder) and the structure of the organization that operates it (ISRG), and we discuss lessons learned from the experience. We also describe the design of ACME, the IETF-standard protocol we created to automate CA--server interactions and certificate issuance, and survey the diverse ecosystem of ACME clients, including Certbot, a software agent we created to automate HTTPS deployment. Finally, we measure Let's Encrypt's impact on the Web and the CA ecosystem. We hope that the success of Let's Encrypt can provide a model for further enhancements to the Web PKI and for future Internet security infrastructure.more » « less
-
We present BGP-iSec, an enhancement of the BGPsec protocol for securing BGP, the Internet’s inter-domain routing protocol. BGP-iSec ensures additional and stronger security properties, compared to BGPsec, without significant extra overhead. The main improvements are: (i) Security for partial adoption: BGP-iSec provides significant security benefits for early adopters, in contrast to BGPsec, which requires universal adoption. (ii) Defense against route leakage: BGP-iSec defends against route leakage, a common cause of misrouting that is not prevented by BGPsec. (iii) Integrity of attributes: BGP-iSec ensures the integrity of integrity-protected attributes, thereby preventing announcement manipulation attacks not prevented by BGPsec. We argue that BGP-iSec achieves these goals using extensive simulations as well as security analysis. The BGP-iSec design conforms, where possible, with the BGPsec design, modifying it only where necessary to improve security or ease deployment. By providing stronger security guarantees, especially for partial adoption, we hope BGP-iSec will be a step towards finally protecting interdomain routing, which remains, for many years, a vulnerability of the Internet’s infrastructure.more » « less
-
more » « less
Network-on-chip (NoC) is widely used as an efficient communication architecture in multi-core and many-core System-on-chips (SoCs). However, the shared communication resources in an NoC platform, e.g., channels, buffers, and routers, might be used to conduct attacks compromising the security of NoC-based SoCs. Most of the proposed encryption-based protection methods in the literature require leaving some parts of the packet unencrypted to allow the routers to process/forward packets accordingly. This reveals the source/destination information of the packet to malicious routers, which can be exploited in various attacks. For the first time, we propose the idea of secure, anonymous routing with minimal hardware overhead to encrypt the entire packet while exchanging secure information over the network. We have designed and implemented a new NoC architecture that works with encrypted addresses. The proposed method can manage malicious and benign failures at NoC channels and buffers by bypassing failed components with a situation-driven stochastic path diversification approach. Hardware evaluations show that the proposed security solution combats the security threats at the affordable cost of 1.5% area and 20% power overheads chip-wide.
-
We use traceroute and BGP data from globally distributed Internet measurement infrastructures to study the impact of a noteworthy submarine cable launch connecting Africa to South America. We leverage archived data from RIPE Atlas and CAIDA Ark platforms, as well as custom measurements from strategic vantage points, to quantify the differences in end-to-end latency and path lengths before and after deployment of this new South-Atlantic cable. We find that ASes operating in South America significantly benefit from this new cable, with reduced latency to all measured African countries. More surprising is that end-to-end latency to/from some regions of the world, including intra-African paths towards Angola, increased after switching to the cable. We track these unintended consequences to suboptimally circuitous IP paths that traveled from Africa to Europe, possibly North America, and South America before traveling back to Africa over the cable. Although some suboptimalities are expected given the lack of peering among neighboring ASes in the developing world, we found two other causes: (i) problematic intra-domain routing within a single Angolese network, and (ii) suboptimal routing/traffic engineering by its BGP neighbors. After notifying the operating AS of our results, we found that most of these suboptimalities were subsequently resolved. We designed our method to generalize to the study of other cable deployments or outages and share our code to promote reproducibility and extension of our work.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- The DOI is not currently available.
