TLDR Tech / Practical
HashDoS attack bypasses hash tables without hash function knowledge
A new black-box HashDoS attack method has been described that can force hash table lookups to require O(n) time instead of O(1) effort, without needing to know the specific hash function. By exploiting string comparison side-channels and timing measurements, the attack can be performed in O(n log n) interactive steps against open addressing systems and Rust's hashbrown hash map. Potential defenses include comparing a full 64-bit hash before processing string keys.
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