The Performance Impact of Elliptic Curve Cryptography on DNSSEC Validation

Abstract

Abstract-The domain name system (DNS) is a core Internet infrastructure that translates names to machine-readable information, such as IP addresses. Security flaws in DNS led to a major overhaul, with the introduction of the DNS security (DNSSEC) extensions. DNSSEC adds integrity and authenticity to the DNS using digital signatures. DNSSEC, however, has its own concerns. It suffers from availability problems due to packet fragmentation and is a potent source of distributed denial-of-service attacks. In earlier work, we argued that many issues with DNSSEC stem from the choice of RSA as default signature algorithm. A switch to alternatives based on elliptic curve cryptography (ECC) can resolve these issues. Yet switching to ECC introduces a new problem: ECC signature validation is much slower than RSA validation. Thus, switching DNSSEC to ECC imposes a significant additional burden on DNS resolvers, pushing load toward the edges of the network. Therefore, in this paper, we study the question: will switching DNSSEC to ECC lead to problems for DNS resolvers, or can they handle the extra load? To answer this question, we developed a model that accurately predicts how many signature validations DNS resolvers have to perform. This allows us to calculate the additional CPU load ECC imposes on a resolver. Using real-world measurements from four DNS resolvers and with two open-source DNS implementations, we evaluate future scenarios where DNSSEC is universally deployed. Our results conclusively show that switching DNSSEC to ECC signature schemes does not impose an insurmountable load on DNS resolvers, even in worst case scenarios.

Roll, Roll, Roll your Root

“…The effects of the root KSK rollover on resolvers studied in this paper are part of the impact of DNSSEC on resolvers. Earlier work studies other aspects of the impact of DNSSEC, including the performance impact of DNSSEC validation [48][49][50][51] and the risks, in terms of availability and security, of packet fragmentation of large DNSSEC responses [11,52]. Even though [11] conclude that up to 10% of resolvers could have problems handling larger DNSSEC responses, we did not observe failures when the DNSKEY response size increased.…”

Establishing Trust in Online Advertising With Signed Transactions

“…RSA keys of 2048 bits provide a security strength of 112 bits, whereas the security strength of both the curve NIST P-256 and the SHA-256 hash algorithm is 128 bits [29]. In terms of performance, comparative studies show that RSA-2048 is faster than ECDSA P-256 for signature verification [30], whereas ECDSA P-256 can outperform RSA producing a signature [31]. However, optimizations on the code and processor architectures may impact the final performance.…”

Making DNSSEC Future Proof

“…The e ects of the root KSK rollover on resolvers studied in this paper are part of the impact of DNSSEC on resolvers. Earlier work studies other aspects of the impact of DNSSEC, including the performance impact of DNSSEC validation [155]- [158] and the risks, in terms of availability and security, of packet fragmentation of large DNSSEC responses [8], [121]. Even though [121] conclude that up to 10% of resolvers could have problems handling larger DNSSEC responses, we did not observe failures when the DNSKEY response size increased.…”

“…None of these protocols, however, have the same constraints as DNSSEC. Van Rijswijk-Deij et al [158] evaluate the performance of Elliptic Curve Cryptography in DNSSEC, but using PQC imposes additional size-requirements.…”

“…Validation Resolvers need to serve their clients as fast as possible. A medium size resolver today processes a few thousand queries per seconds resulting in a few hundred validations [158]. This is far below their maximum capacity.…”