Handling Encryption in an Analysis for Secure Information Flow

Abstract

Abstract. This paper presents a program analysis for secure information flow. The analysis works on a simple imperative programming language containing a cryptographic primitive-encryption-as a possible operation. The analysis captures the intuitive qualities of the (lack of) information flow from a plaintext to its corresponding ciphertext. The analysis is proved correct with respect to a complexity-theoretical definition of the security of information flow. In contrast to the previous results, the analysis does not put any restrictions on the structure of the program, especially on the ways of how the program uses the encryption keys.

Security Protocol Verification: Symbolic and Computational Models

“…It also provides a bound on the probability of success of an attack. It considerably extends early work by Laud [141,142] which was limited either to passive adversaries or to a single session of the protocol. More recently, Tšahhirov and Laud [144,177] developed a tool similar to CryptoVerif but that represents games by dependency graphs; it handles public-key and shared-key encryption and proves secrecy properties.…”

Towards a Type System for Security APIs

“…Laud [13] presents a weakened variant of non-interference termed 'computational independence, ' using static analysis to track dependencies between variables. Security is guaranteed when the public outputs are computationally independent from all of the sensitive inputs.…”

A security domain model to assess software for exploitable covert channels

“…Other work in using sound type systems for secure information flow has focused on areas such as: encryption and decryption of information, where flows from plaintext (High) information to ciphertext (Low) information must be addressed in light of noninterference rules that would seem to prevent such interaction [21] [35]; probabilistic noninterference, where probability distributions are used to determine a likelihood of noninterference from High to Low variables, primarily for multi-threaded processes where scheduling is nondeterministic [39][31] [36]; and type inference, in which the flow of information is automatically determined based on semantic analysis [34] [7]. Eventually, Smith & Thober [37] enhanced the linguistic model of secure information flow such that sensitivity labels need be assigned only at I/O boundaries, while the labels of variables and constants, as well as data information flow through a program's execution, are automatically derived relative to the I/O (device) labels.…”