Shir Landau Feibish, Y. Afek, A. Bremler-Barr, E. Cohen, Michal Shagam
{"title":"Mitigating DNS random subdomain DDoS attacks by distinct heavy hitters sketches","authors":"Shir Landau Feibish, Y. Afek, A. Bremler-Barr, E. Cohen, Michal Shagam","doi":"10.1145/3132465.3132474","DOIUrl":"https://doi.org/10.1145/3132465.3132474","url":null,"abstract":"Random Subdomain DDoS attacks on the Domain Name System (DNS) infrastructure are becoming a popular vector in recent attacks (e.g., recent Mirai attack on Dyn). In these attacks, many queries are sent for a single or a few victim domains, yet they include highly varying non-existent subdomains generated randomly. Motivated by these attacks we designed and implemented novel and efficient algorithms for distinct heavy hitters (dHH). A (classic) heavy hitter (HH) in a stream of elements is a key (e.g., the domain of a query) which appears in many elements (e.g., requests). When stream elements consist of ¡key, subkey¿ pairs, (¡domain, subdomain¿) a distinct heavy hitter (dhh) is a key that is paired with a large number of different subkeys. Our algorithms dominate previous designs in both the asymptotic (theoretical) sense and practicality. Specifically the new fixed-size algorithms are simple to code and with asymptotically optimal space accuracy tradeoffs. Based on these algorithms, we build and implement a system for detection and mitigation of Random Subdomain DDoS attacks. We perform experimental evaluation, demonstrating the effectiveness of our algorithms.","PeriodicalId":411240,"journal":{"name":"Proceedings of the fifth ACM/IEEE Workshop on Hot Topics in Web Systems and Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130594033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"NoCDN: scalable content delivery without a middleman","authors":"Junbo Xu, M. Rabinovich","doi":"10.1145/3132465.3132476","DOIUrl":"https://doi.org/10.1145/3132465.3132476","url":null,"abstract":"Today's websites achieve scalability by either deploying their own platforms with sufficient spare capacity or signing up for services from a content delivery network (CDN). This paper investigates another alternative, where a website directly recruits Internet users to contribute their resources to help deliver the site's content. We show that this alternative, which we call NoCDN, can be implemented securely, transparently to the users accessing the site, and without changes to the content itself.","PeriodicalId":411240,"journal":{"name":"Proceedings of the fifth ACM/IEEE Workshop on Hot Topics in Web Systems and Technologies","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132943712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nancy Carter, Cheng Li, Qun A. Li, J. Stevens, Ed Novak, Zhengrui Qin, Jiquo Yu
{"title":"Graphical passwords for older computer users","authors":"Nancy Carter, Cheng Li, Qun A. Li, J. Stevens, Ed Novak, Zhengrui Qin, Jiquo Yu","doi":"10.1145/3132465.3132472","DOIUrl":"https://doi.org/10.1145/3132465.3132472","url":null,"abstract":"Traditional text password authentication is widely used to gain access to computing resources. Older users find the cognitive effort, and manual dexterity skills needed to use strong text passwords challenging. We designed and evaluated our Graphical Password system based on touchscreen selection of familiar facial images embedded randomly among unfamiliar, yet similar images. In our usability study, older users demonstrated a recall rate of 97%, password entropy superior to short PINs, and authentication time comparable to short text passwords.","PeriodicalId":411240,"journal":{"name":"Proceedings of the fifth ACM/IEEE Workshop on Hot Topics in Web Systems and Technologies","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134221956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enabling distributed revision control systems in delay-tolerant networks","authors":"Philipp Hagemeister, M. Mauve","doi":"10.1145/3132465.3132466","DOIUrl":"https://doi.org/10.1145/3132465.3132466","url":null,"abstract":"A distributed revision control system (dRCS) such as git or mercurial allows users to track changes1 to a common document.2 When multiple users commit, a primary challenge of a dRCS becomes to provide one view of the current repository state.","PeriodicalId":411240,"journal":{"name":"Proceedings of the fifth ACM/IEEE Workshop on Hot Topics in Web Systems and Technologies","volume":"178 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121467011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Proceedings of the fifth ACM/IEEE Workshop on Hot Topics in Web Systems and Technologies","authors":"","doi":"10.1145/3132465","DOIUrl":"https://doi.org/10.1145/3132465","url":null,"abstract":"","PeriodicalId":411240,"journal":{"name":"Proceedings of the fifth ACM/IEEE Workshop on Hot Topics in Web Systems and Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125842597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}