Weak key attacks

فهرست عناوین اصلی در این پاورپوینت

فهرست عناوین اصلی در این پاورپوینت

● 802.11i Overview
● Presentation Objectives
● Agenda
● What is it?
● How does WEP “work”?
● Review of the cipher RC4
● Collision attacks
● Weak key attacks
● Replay attacks
● Forgery attacks
● Ill-defined goals = attacker success
● Architectural Components
● Goals
● Authentication and Key Management Architecture
● 802.11 Operational Phases
● Purpose of each phase (1)
● Purpose of each phase (2)
● Data Transfer Overview
● Data Transfer Requirements
● Filtering
● Replay Mechanisms
● TKIP Summary
● TKIP design challenges
● TKIP MPDU Format
● TKIP Keys
● TKIP Design (1) — Michael
● TKIP Countermeasures
● TKIP Design (3)
● TKIP Design (4)
● CCMP
● Counter Mode with CBC-MAC
● CCM Mode Overview
● CCM Properties
● CCM Usage by CCMP
● CCMP MPDU Format
● Long-term Solution Summary
● Data Transfer Summary
● 802.1X Key Management
● Pairwise Key Hierarchy
● Key Management Overview
● Step 1: Push PMK to AP
● EAPoL Key Message
● Step 2: 4-Way Handshake
● Step3: Group Key Handshake
● One Last Detail
● Key Management Summary
● Authentication Requirements
● Authentication Components
● Authentication Overview
● Digging Deeper: EAP (1)
● Digging Deeper: EAP (2)
● Digging Deeper: EAP (3)
● Digging Deeper: EAP (4)
● 802.1X
● RADIUS (1)
● RADIUS (2)
● RADIUS (3)
● Digging Deeper: EAP-TLS
● Example –EAP-TLS (1)
● Example – EAP-TLS (2)
● Authentication Summary
● Discovery Overview
● Discovery
● Discovery Summary
● Other 802.11i Features
● Pre-authentication
● PEAP Overview
● PEAP Man-in-Middle Attack
● Pre-shared Key
● Ad hoc networks
● Password-to-Key Mapping
● Randomness Needed
● 802.11i Summary
● Feedback?

نوع زبان: انگلیسی حجم: 0.9 مگا بایت
نوع فایل: اسلاید پاورپوینت تعداد اسلایدها: 75 صفحه
سطح مطلب: نامشخص پسوند فایل: ppt
گروه موضوعی: زمان استخراج مطلب: 2019/05/17 04:41:28

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عبارات مهم استفاده شده در این مطلب

عبارات مهم استفاده شده در این مطلب

key, intel, confidential, internal, datum, wep, packet, be, –, what, wrong, transfer,

توجه: این مطلب در تاریخ 2019/05/17 04:41:28 به صورت خودکار از فضای وب آشکار توسط موتور جستجوی پاورپوینت جمع آوری شده است و در صورت اعلام عدم رضایت تهیه کننده ی آن، طبق قوانین سایت از روی وب گاه حذف خواهد شد. این مطلب از وب سایت زیر استخراج شده است و مسئولیت انتشار آن با منبع اصلی است.

https://gsyc.urjc.es/~anto/ubicuos2/wifi/80211iOverview.ppt

در صورتی که محتوای فایل ارائه شده با عنوان مطلب سازگار نبود یا مطلب مذکور خلاف قوانین کشور بود لطفا در بخش دیدگاه (در پایین صفحه) به ما اطلاع دهید تا بعد از بررسی در کوتاه ترین زمان نسبت به حدف با اصلاح آن اقدام نماییم. جهت جستجوی پاورپوینت های بیشتر بر روی اینجا کلیک کنید.

عبارات پرتکرار و مهم در این اسلاید عبارتند از: key, intel, confidential, internal, datum, wep, packet, be, –, what, wrong, transfer,

مشاهده محتوای متنیِ این اسلاید ppt

مشاهده محتوای متنیِ این اسلاید ppt

۸ ۲.۱۱i overview jesse walker intel corporation jesse.walker@intel.com intel confidential internal use only presentation objectives outline security problems in ۸ ۲.۱۱ ۱۹۹۹ communicate what ieee ۸ ۲.۱۱i is and how it works intel confidential internal use only agenda what’s wrong with wep architecture data transfer key management authentication security capabilities discovery other features intel confidential internal use only what is it ieee std ۸ ۲.۱۱ ۱۹۹۹ defines wireless equivalent privacy wep protocol intended to effect privacy … …because anyone with a radio receiver can eavesdrop wep’s goals create the privacy achieved by a wired network not a well defined testable goal wep vulnerabilities discovered wep broken walker oct ۲ borisov et. al. jan ۲ ۱ fluhrer mantin shamir aug ۲ ۱ what’s wrong with wep intel confidential internal use only how does wep work what’s wrong with wep intel confidential internal use only review of the cipher rc۴ plaintext data byte p decryption works the same way p c  b thought experiment what happens when p۱ and p۲ are encrypted under the same key stream byte b c۱ p۱  b c۲ p۲  b then c۱  c۲ p۱  b  p۲  b p۱  p۲ what’s wrong with wep intel confidential internal use only collision attacks wep expands each rc۴ key into ۲۲۴ per packet keys  data can be recovered if iv is ever repeated with same key  rc۴ key must be changed at least every ۲۲۴ packets or data is exposed through iv collisions some implemented iv selection strategies random collision probability pn two packets will share same iv after n packets is p۲ ۱ ۲۲۴ for n ۲ and pn pn–۱ n–۱ ۱–pn–۱ ۲۲۴ for n ۲. ۵ chance of a collision exists already after only ۴۸۲۳ packets increment from collision probability ۱ after two devices transmit what’s wrong with wep intel confidential internal use only weak key attacks class of rc۴ weak keys exists where patterns in the ۱st ۳ bytes of key causes corresponding patterns in ۱st few bytes of the generated rc۴ key stream. for each packet use iv and exposed key stream to identify potential weak keys iterate over potential weak keys from a sequence of packets until the rc۴ base key is found what’s wrong with wep intel confidential internal use only replay attacks what’s wrong with wep intel confidential internal use only forgery attacks sample attack ۱ recv addr src addr dest addr are all unprotected on packets from a sta to the ap corrupt the dest addr the ap will decrypt data and send it to the forged destination sample attack ۲ create a blank message with same number of data bytes flip some bits and compute the icv xor resulting bit flipped message icv into captured message … … ۱ new icv what’s wrong with wep intel confidential internal use only ill defined goals attacker success aims must be translated into measurable technical objectives doesn’t solve the right problems to achieve goals securing a wlan is like securing a submarine closing only a few of the hatches doesn’t help if you’re not a professional don’t indulge in crypto design s.s. wep what’s wrong with wep intel confidential internal use only architectural components goals eap ۸ ۲.۱x radius operational phases discovery authentication key management data transfer architecture intel confidential internal use only goals replace wep by protocol that properly uses encryption add data authenticity and integrity decrypted data doesn’t mean anything if you don’t know who sent it add proper authentication manufacture fresh keys can’t efficiently defeat replay without fresh keys encryption harder to get right without fresh keys tie data link keys to the authentication must prove each packet received is authorized architecture intel confidential internal use only authentication and key management architecture ۸ ۲.۱x eapol ۸ ۲.۱۱ architecture intel confidential internal use only ۸ ۲.۱۱ operational phases architecture intel confidential internal use only purpose of each phase ۱ discovery determine promising parties with whom to communicate ap advertises network security capabilities to stas ۸ ۲.۱x authentication centralize network admission policy decisions at the as sta determines whether it does indeed want to communicate mutually authenticate sta and as generate master key as a side effect of authentication use master key to generate session keys authorization token architecture intel confidential internal use only purpose of each phase ۲ radius based key distribution as moves not copies session key pmk to sta’s ap ۸ ۲.۱x key management bind pmk to sta and ap confirm both ap and sta possess pmk generate fresh operational key ptk prove each peer is live synchronize ptk use architecture intel confidential internal use only data transfer overview ۸ ۲.۱۱i defines ۲ protocols to protect data transfer tkip – for legacy devices only ccmp – better security for new devices two protocols instead of one due to politics data transfer intel confidential internal use only data transfer requirements never send or receive unprotected packets message origin authenticity — prevent forgeries sequence packets — detect replays avoid rekeying — ۴۸ bit packet sequence number eliminate per packet key – don’t misuse encryption protect source and destination addresses use one strong cryptographic primitive for both confidentiality and integrity interoperate with proposed quality of service qos enhancements ieee ۸ ۲.۱۱ tge data transfer intel confidential internal use only filtering data transfer begin filtering non ۸ ۲.۱x data mpdus begin filtering non ۸ ۲.۱x data mpdus intel confidential internal use only replay mechanisms ۴۸ bit iv used for replay detection first four bits of iv indicate qos traffic class remaining ۴۴ bits used as counter decryption integrity check fail if traffic class bits are altered sender uses single counter space but receiver needs one for each traffic class aes with ccm or ocb authenticated encryption ccm is mandatory and ocb is optional header authentication payload authentication and confidentiality data transfer intel confidential internal use only tkip summary tkip …

کلمات کلیدی پرکاربرد در این اسلاید پاورپوینت: key, intel, confidential, internal, datum, wep, packet, be, –, what, wrong, transfer,

این فایل پاورپوینت شامل 75 اسلاید و به زبان انگلیسی و حجم آن 0.9 مگا بایت است. نوع قالب فایل ppt بوده که با این لینک قابل دانلود است. این مطلب برگرفته از سایت زیر است و مسئولیت انتشار آن با منبع اصلی می باشد که در تاریخ 2019/05/17 04:41:28 استخراج شده است.

https://gsyc.urjc.es/~anto/ubicuos2/wifi/80211iOverview.ppt

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