Impact of a non-deterministic rekey interval on the performance of arc4random

TL;DR

This paper examines how introducing a non-deterministic rekey interval to the arc4random PRNG affects its performance and rekeying behavior, showing slight performance improvements and successful randomization of rekey intervals.

Contribution

It presents a modification to arc4random to implement a non-deterministic rekey interval and evaluates its impact on performance and security.

Findings

Slight performance increase observed

Rekey interval successfully randomized

Modification maintains core functionality

Abstract

This paper is intended to provide the readers with a clear understanding of the modification done to the pseudo-random number generator (PRNG) arc4random. The arc4random PRNG was modified to implement a non-deterministic rekey interval. A comparison was made with the unpatched version regarding performance and the rekey interval's randomization. All measurements were done when the rekey was performed. A slight increase in performance was observed, and the rekey interval was randomized as expected.