TAILIEUCHUNG - Public-Key Cryptography and Message Authentication

Requirements - must be able to verify that: 1. Message came from apparent source or author, 2. Contents have not been altered, 3. Sometimes, it was sent at a certain time or sequence. Protection against active attack (falsification of data and transactions) | Chapter3 Public-Key Cryptography and Message Authentication Henric Johnson Blekinge Institute of Technology, Sweden Henric Johnson OUTLINE Approaches to Message Authentication Secure Hash Functions and HMAC Public-Key Cryptography Principles Public-Key Cryptography Algorithms Digital Signatures Key Management Henric Johnson Authentication Requirements - must be able to verify that: 1. Message came from apparent source or author, 2. Contents have not been altered, 3. Sometimes, it was sent at a certain time or sequence. Protection against active attack (falsification of data and transactions) Henric Johnson Approaches to Message Authentication Authentication Using Conventional Encryption Only the sender and receiver should share a key Message Authentication without Message Encryption An authentication tag is generated and appended to each message Message Authentication Code Calculate the MAC as a function of the message and the key. MAC = F(K, M) Henric Johnson Henric Johnson One-way HASH function Henric Johnson One-way HASH function Secret value is added before the hash and removed before transmission. Henric Johnson Secure HASH Functions Purpose of the HASH function is to produce a ”fingerprint. Properties of a HASH function H : H can be applied to a block of data at any size H produces a fixed length output H(x) is easy to compute for any given x. For any given block x, it is computationally infeasible to find x such that H(x) = h For any given block x, it is computationally infeasible to find with H(y) = H(x). It is computationally infeasible to find any pair (x, y) such that H(x) = H(y) Henric Johnson Simple Hash Function One-bit circular shift on the hash value after each block is processed would improve Henric Johnson Message Digest Generation Using SHA-1 Henric Johnson SHA-1 Processing of single 512-Bit Block Henric Johnson Other Secure HASH functions SHA-1 .

• An ninh - Bảo mật
• Message Authentication
• Public Key Cryptography
• network security
• information security
• security mechanisms
• security services
• security architecture
• encryption system
• Message Integrity
• An toàn thông tin
• Bảo mật thông tin
• Cryptography & Network Security
• Cryptography & Network Security Exercise
• Authentication requirements
• Authentication Functions
• Message encryption
• Message Authentication Code
• Data security
• Lecture Data security and encryption
• Mã hóa dữ liệu
• Bảo mật dữ liệu
• Message authentication using encryption
• Message Confidentiality
• Lecture Cryptography and network security
• Cryptography and network security
• Checking Integrity
• Cryptographic Hash Function Criteria
• Network security technologies
• Ebook Network security technologies
• Security in network design
• Basic confidentiality technologies
• Basic authentication technologies
• Basic message integrity technologies
• Lecture notes on Computer and network security
• Computer security
• Hash function
• Birthday attack
• Cryptography engineering
• The context of cryptography
• Introduction to cryptography
• Block ciphers
• Block cipher modes
• Hash functions
• Message authentication codes
• Introduction to modern cryptography
• Modern cryptography
• Classical cryptography
• Perfectly secret encryption
• Practical constructions
• Data security and encryption
• Symmetric ciphers
• Asymmetric ciphers
• Cryptographic data integrity algorithms
• Mutual trust
• Operating systems
• Lecture Operating systems
• Hệ điều hành
• Distributed system security
• Message security
• Authentication of data
• Number theory
• Modular arithmetic with integers
• Bài giảng An toàn hệ thống thông tin
• An toàn hệ thống thông tin
• Hệ thống thông tin
• Mã xác thực thông điệp
• Digital Signature
• Signing the Digest
• Digital Signature Standard