[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"branding":3,"analytics":7,"article-kv-cache-timing-attacks-falter-under-real-server-load":10,"sections":35},{"siteName":4,"siteTagline":5,"publisherName":4,"contactEmail":6},"The Revision","Tech news, decoded.","editor@therevision.news",{"gaMeasurementId":8,"adsenseClientId":9},"G-ZW2MV82GYR","ca-pub-8533917693782264",{"article":11},{"id":12,"slug":13,"title":14,"dek":15,"body_md":16,"tags_json":17,"published_at":18,"created_at":19,"updated_at":20,"status":21,"review_note":22,"review_notes":23,"image_url":22,"persona_id":22,"persona_name":22,"section":24,"tags":25,"sources":30,"feedback":34,"feedback_at":22,"cost_usd":34,"total_tokens":34},6230,"kv-cache-timing-attacks-falter-under-real-server-load","KV-Cache Timing Attacks Falter Under Real Server Load","A new study finds that timing attacks exposing shared LLM cache hits are reliable in quiet labs but degrade sharply under realistic multi-tenant traffic.","A timing side channel that lets one tenant on a shared LLM server guess whether another tenant's prompt prefix is already cached works well in a quiet lab and much less well once real traffic shows up.\n\nResearchers ran seven experiments against live multi-tenant LLM-serving systems to test how reliable KV-cache timing attacks actually are under load. On a vLLM server running DeepSeek-R1-Distill-Llama-8B on Nvidia GB10 hardware, the attack's effect size (Cohen's d) fell from 0.7789 with no competing traffic to 0.2109 once just two synthetic workers were added, and detection accuracy (AUROC) dropped from 0.650 at idle to as low as 0.531 around 61 percent server overlap. The same collapse showed up on a real two-node, two-GPU tensor-parallel vLLM setup, where effect size fell from 3.418 to 0.511. Two pilot tests on SGLang, a competing serving engine, were statistically inconclusive.\n\nThis matters because KV-cache side channels have been pitched as a real privacy risk for shared LLM infrastructure - a way to infer what other users, or even a company's hidden system prompt, are sending to the same model. This paper is a useful corrective: most published demonstrations of the attack were measured on quiet, uncontended systems, which overstates how reliable the leak is in production. But the drop-off is not a clean kill switch - concurrency-depth variance strongly predicts when the attack still works, so an attacker who can time requests around traffic lulls keeps some edge.\n\nIn other words, the exploit does not disappear under load, it just gets noisier - which is a familiar story for side-channel attacks that look damning in a paper and merely inconvenient in a data center.","[\"llm-security\",\"side-channel-attack\",\"kv-cache\",\"multi-tenant-serving\"]","2026-09-10T04:00:00.000Z","2026-09-10T08:12:02.137Z","2026-09-10T08:12:14.110Z","published",null,[],"security",[26,27,28,29],"llm-security","side-channel-attack","kv-cache","multi-tenant-serving",[31],{"name":32,"url":33},"arXiv cs.AI","https:\u002F\u002Farxiv.org\u002Fabs\u002F2609.06853",0,{"sections":36},[37,42,45,50,55,60,65,69,74,79,84,89,94,99],{"name":38,"slug":39,"count":40,"latest_published_at":41},"AI","ai",3480,"2026-09-11T04:00:00.000Z",{"name":43,"slug":24,"count":44,"latest_published_at":41},"Security",628,{"name":46,"slug":47,"count":48,"latest_published_at":49},"Policy","policy",336,"2026-09-11T00:56:21.000Z",{"name":51,"slug":52,"count":53,"latest_published_at":54},"Deals","deals",179,"2026-06-29T20:02:07.000Z",{"name":56,"slug":57,"count":58,"latest_published_at":59},"Hardware","hardware",153,"2026-09-09T15:12:32.000Z",{"name":61,"slug":62,"count":63,"latest_published_at":64},"Consumer Tech","consumer-tech",99,"2026-09-09T17:27:33.000Z",{"name":66,"slug":67,"count":68,"latest_published_at":41},"Science","science",98,{"name":70,"slug":71,"count":72,"latest_published_at":73},"Software","software",75,"2026-09-10T20:41:21.000Z",{"name":75,"slug":76,"count":77,"latest_published_at":78},"Dev Tools","dev-tools",69,"2026-08-18T04:00:00.000Z",{"name":80,"slug":81,"count":82,"latest_published_at":83},"Startups","startups",55,"2026-09-09T23:14:29.000Z",{"name":85,"slug":86,"count":87,"latest_published_at":88},"Gaming","gaming",43,"2026-09-10T12:18:06.000Z",{"name":90,"slug":91,"count":92,"latest_published_at":93},"General","general",41,"2026-09-08T01:57:23.000Z",{"name":95,"slug":96,"count":97,"latest_published_at":98},"Reviews","reviews",20,"2026-06-24T12:00:01.000Z",{"name":100,"slug":101,"count":102,"latest_published_at":103},"How-To","how-to",6,"2026-06-16T09:00:00.000Z"]