# Protect against hash attacks

**URL:** <https://discuss.dgraph.io/t/protect-against-hash-attacks/8420>\
**Category:** Ristretto\
**Tags:** ristretto, kind:enhancement, priority:p2, status:accepted\
**Created:** [January 31, 2020, 12:45am UTC](https://discuss.dgraph.io/t/protect-against-hash-attacks/8420 "2020-01-31T00:45:37Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![diggy](https://yyz1.discourse-cdn.com/flex007/user_avatar/discuss.dgraph.io/diggy/32/3666_2.png) [@diggy](https://discuss.dgraph.io/u/diggy)\
**Post date:** [January 31, 2020, 12:45am UTC](https://discuss.dgraph.io/t/protect-against-hash-attacks/8420/1 "2020-01-31T00:45:37Z")

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**Moved from GitHub [ristretto/131](https://github.com/dgraph-io/ristretto/issues/131)**

_Posted by_ [martinmr](https://github.com/martinmr):

An attacker can prevent new items from being accepted by the policy by artificially raising the frequency of the victim.

Caffeine code: [caffeine/BoundedLocalCache.java at 8bdfb0d95db523d15c2560f05a228468ecdbe98d · ben-manes/caffeine · GitHub](https://github.com/ben-manes/caffeine/blob/8bdfb0d95db523d15c2560f05a228468ecdbe98d/caffeine/src/main/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java#L752-L776)