ImageVerifierCode 换一换
格式:PPT , 页数:22 ,大小:816.50KB ,
资源ID:378723      下载积分:2000 积分
快捷下载
登录下载
邮箱/手机:
温馨提示:
如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
如填写123,账号就是123,密码也是123。
特别说明:
请自助下载,系统不会自动发送文件的哦; 如果您已付费,想二次下载,请登录后访问:我的下载记录
支付方式: 支付宝扫码支付 微信扫码支付   
注意:如需开发票,请勿充值!
验证码:   换一换

加入VIP,免费下载
 

温馨提示:由于个人手机设置不同,如果发现不能下载,请复制以下地址【http://www.mydoc123.com/d-378723.html】到电脑端继续下载(重复下载不扣费)。

已注册用户请登录:
账号:
密码:
验证码:   换一换
  忘记密码?
三方登录: 微信登录  

下载须知

1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。
2: 试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。
3: 文件的所有权益归上传用户所有。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 本站仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

版权提示 | 免责声明

本文(Authentication for Humans.ppt)为本站会员(hopesteam270)主动上传,麦多课文库仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文库(发送邮件至master@mydoc123.com或直接QQ联系客服),我们立即给予删除!

Authentication for Humans.ppt

1、Authentication for Humans,Rachna Dhamija SIMS, UC Berkeley rachnasims.berkeley.eduDIMACS Workshop on Usable Privacy and Security Software July 7, 2004,Talk Outline,Machines Authenticating Users Dj Vu User Study- Using Images for AuthenticationUsers Authenticating Remote Servers Interfaces for websit

2、e authentication,Password Usability and Security,Simple and meaningful passwords - Memorable, but easier to guessComplex passwords - Strong, but hard to rememberAdvantages of passwords Cheap and easy to implement We develop muscle memory,Previous Solutions,Stronger password hashing & storage Proacti

3、ve password cracking Enforce system policies Better user education and training Significant non compliance rate by usersWe try to address the fundamental problem: Recall is hard,Picture recognition is easier,Humans have a vast memory for pictures 2560 photos for a few seconds: 90% recognition Standi

4、ng, Conezio, Haber 10,000 photos: 66% recognition after 2 days Standing 200 random photos: 90% after 1-3 months Weinshal/Kirkpatrik, CHI2004 Fractions of a second is enough to remember Picture recognition is easier than verbal recognition Picture recognition is easier than picture recall Harder to r

5、ecall semantics or to redraw picture But picture recall is better than verbal recall,Dj Vu Design Goals,Base security on human strengths Recognition over recallPrevent weak passwordsPrevent password sharingNo biometrics or tokens,Authentication through Images,Choose image portfolio Challenge set = p

6、ortfolio + decoys Photos and Random Art,Random Art,Algorithm: seed - pseudo-random number generator- random expression tree maps pixels to RGB - random art,Choose Image Portfolio,Portfolio Training,Challenge,Portfolio Creation Screen,Login Screen,Attacks,Brute Force optimal portfolio and challenge d

7、epends on security 5 image portfolio/25 challenge set = 53,130 combinationsMeasures against shoulder surfers: hide image selection distort images Measures against Intersection Attack: Always show same challenge set Multi-stage authentication,Experiment Design,Target population = general computer use

8、rs20 participants (11 males + 9 females, expert/novice),Initialization PIN (4 digits) Password (6 char.) Art portfolio (5/100) Photo portfolio (5/100),Login PIN Password Art (5/25) Photo (5/25),Repeat login after one weekTask order randomizedPortfolio creation- same images but random order Portfolio

9、 login- random images and random order,Task Completion Time,Unlimited time & attempts Does not include failed logins,Error Rate,Session 1: no unrecoverable errors made with portfolios Session 2: significantly less failed logins with portfolios (all users remembered 4/5 images on first attempt),More

10、Results,Its easier than it looksText vs. image portfolios Passwords/PINS faster to create art is individual Art descriptions vary, hard to describe How hard are they to communicate? Spouse-proof?,Conclusions in this study,Recognition-based authentication More reliable long term than passwords, PINs

11、Easier, more pleasant to use Random Art portfolios are harder to predict than passwords or real imagesApplications Where text input is hard, limited observation (e.g., ATM, PDA, pen-based devices) Infrequently used high availability passwords,Future Work,Long term studies Frequency of use Multiple p

12、ortfolios and changes Portfolio communication & prediction study Cued recall of text passwordsImage Generation & Distortion Image generation and distortion techniques What is the space of images are distinguishable, memorable?Strengthen against attack, improve login times, allow non-perfect probabilistic recognition,Talk Outline,Machines Authenticating Users Dj Vu User Study Users Authenticating Remote Servers Interfaces for website authentication,Challenge,

copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
备案/许可证编号:苏ICP备17064731号-1