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WPA là một giải pháp tình thế  WPA2 là chuẩn IEEE 802.11i  802.11i dùng khái niệm an ninh mạng mạnh mẽ(RSN -Robust Security Network)  Khác biệt lớn nhất: AES được dùng cho mã hóa  Mã hóa AES được thực hiện trong phần cứng  Đòi hỏi bộ xử lý mạnh hơn

38 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 137 | Lượt tải: 0

three broad lines of defense: 1. attack prevention & preemption (before) 2. attack detection & filtering (during) 3. attack source traceback & ident (after)  huge range of attack possibilities  hence evolving countermeasures

28 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 137 | Lượt tải: 0

Evolution of information systems Now everyone want to be on the Internet Interconnect networks has persistent security concerns ▫ can’t easily secure every system typically use a Firewall to provide perimeter defence as part of comprehensive security strategy

32 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 123 | Lượt tải: 0

most promising approach to improving password security allow users to select own password but have system verify it is acceptable ▫ simple rule enforcement (see earlier slide) ▫ compare against dictionary of bad passwords ▫ use algorithmic (markov model or bloom filter) to detect poor choices

25 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 126 | Lượt tải: 0

Internet Security Association and Key Management Protocol provides framework for key management defines procedures and packet formats to establish, negotiate, modify, & delete SAs independent of key exchange protocol, encryption alg, & authentication method

20 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 132 | Lượt tải: 0

merchant sends payment gateway a payment capture request gateway checks request then causes funds to be transferred to merchants account notifies merchant using capture response

27 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 124 | Lượt tải: 0

Does not rely on certificate authorities in PGP every user is own CA ▫ can sign keys for users they know directly (certificates are like X.509) forms a “web of trust” ▫ trust keys have signed ▫ can trust keys others have signed if have a chain of signatures to them key ring includes trust indicators users can also revoke their keys

26 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 123 | Lượt tải: 0

(Step 1) Key generation: Every entity generates a public-private key pair ▫ choose a random private key ▫ compute the public key (Step 2) Registration: Every entity should ▫ provide proof of their identity (to the CA) (Step 3) Obtain certificate from the CA ▫ CA signs a certificate which binds the identity of A to A’s public key

23 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 136 | Lượt tải: 0

Sheart of the algorithm processing message in 1024-bit blocks consists of 80 rounds ▫ updating a 512-bit buffer ▫ using a 64-bit value Wt derived from the current message block ▫ and a round constant based on cube root of first 80 prime numbers

32 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 138 | Lượt tải: 0

Based on the difficulty of discrete log problem (like DH) All entities agree on a prime p (say 200 digits long) and a generator g Alice chooses a random value a as her private key (a < p also has typically the same number of digits as p) Alice compute α = ga mod p as her public key

67 trang | Chia sẻ: nguyenlam99 | Ngày: 10/01/2019 | Lượt xem: 130 | Lượt tải: 0