Paper Info
Title
Security in the Presence of Key Reuse: Context-Separable Interfaces and their Applications.
Abstract
Key separation is often difficult to enforce in practice. While key reuse can be catastrophic for security, we know of a number of cryptographic schemes for which it is provably safe. But existing formal models, such as the notions of joint security (Haber-Pinkas, CCS '01) and agility (Acar et al., EUROCRYPT '10), do not address the full range of key-reuse attacks-in particular, those that break the abstraction of the scheme, or exploit protocol interactions at a higher level of abstraction. This work attends to these vectors by focusing on two key elements: the game that codifies the scheme under attack, as well as its intended adversarial model; and the underlying interface that exposes secret key operations for use by the game. Our main security experiment considers the implications of using an interface (in practice, the API of a software library or a hardware platform such as TPM) to realize the scheme specified by the game when the interface is shared with other unspecified, insecure, or even malicious applications. After building up a definitional framework, we apply it to the analysis of two real-world schemes: the EdDSA signature algorithm and the Noise protocol framework. Both provide some degree of context separability, a design pattern for interfaces and their applications that aids in the deployment of secure protocols.
Year
DOI
Venue
2019
10.1007/978-3-030-26948-7_26
ADVANCES IN CRYPTOLOGY - CRYPTO 2019, PT 1
Keywords
Field
DocType
Key reuse,APIs,Diffie-Hellman,EdDSA,Noise
EdDSA,Software deployment,Cryptography,Reuse,Computer science,Computer security,Exploit,Theoretical computer science,Digital Signature Algorithm,Diffie–Hellman key exchange,Design pattern
Journal
Volume
ISSN
Citations 
11692
0302-9743
0
PageRank 
References 
Authors
0.34
0
2
Name
Order
Citations
PageRank
Christopher Patton152.45
Thomas Shrimpton2132060.19