This document discusses cryptographic hash algorithms and focuses on MD5. It lists common hash algorithms and their applications such as file integrity verification and password storage. It then provides details on MD5, describing how it is a 128-bit hash function that was designed in 1991 as a replacement for MD4. The document outlines the MD5 algorithm, providing examples of how it hashes messages, and describes how it has been employed in security applications but is now considered broken due to collisions being found.

1. WelcomePresentation onCryptography & Information Security

2. Topic5List cryptographic hash algorithms and list their applications. Discuss MD5 hash algorithm or any other hash algorithm in detail.Submitted By:Muhammad AshikIqbalM.Sc. in CSEID: 092-25-127DIUashik.email@gmail.comhttp://ashikiqbal.blogspot.com

3. Cryptographic Hash Algorithms

4. List of Hash Algorithms

5. Applications of Hash AlgorithmsUsed AloneFile integrity verificationPublic key fingerprintPassword storageCombined with encryption functions

6. MD5Message-Digest algorithm 5

7. MD5Designed by Ronald Rivest in 1991 and replaces an earlier hash function MD4MD5 is a widely used cryptographic hash function128-bit hash functionUses 512 bit blocksUses 128-bit keys or statesThe 128-bit key is split into 4 sub-keys of 32 bits eachFour rounds are used to produce the hashIn each round addition, XOR, AND, OR, rotation are used

8. MD5 Examplehello5d41402abc4b2a76b9719d911017c592

9. MD5 Algorithms2. Append length (64bits)1. Append padding bits(to 448 mod 512)3. Initialize MD bufferWord A = 01 23 45 67Word B = 89 AB CD EFWord C = FE DC BA 98Word D = 76 54 32 10

10. MD5 AlgorithmsF(X,Y,Z) = (X ∧ Y) ∨ (¬X ∧ Z)G(X,Y,Z) = (X ∧ Z) ∨ (Y ∧ ¬Z)H(X,Y,Z) = X ⊕ Y ⊕ ZI(X,Y,Z) = Y ⊕ (X ∨ ¬Z)Round 0: Steps 0 to 15Round 1: Steps 16 to 31Round 2: Steps 32 to 4716 stepsRound 4: Steps 47 to 63X[k] = M [q*16+k] (32 bit)Constructed from sine function

11. MD5 ApplicationsMD5 has been employed in a wide variety of security applications and is also commonly used to check the integrity of filesUsed in the software world to provide some assurance that a transferred file has arrived intactUnix-based operating systems include MD5 sum utilities in their distribution packagesMD5 can provide error-checking functionalityIt recognizes corrupt or incomplete download, which becomes more likely when downloading larger filesWidely used to store passwords after adding salt

12. MD5 Attack HistoryDobbertin “almost” able to break MD5 using his MD4 attack in 1996Showed that MD5 might be at riskIn 2004, Wang published one MD5 collisionNo explanation of method was givenBased on one collision, Wang’s method was reverse engineered by Australian teamIronically, this reverse engineering work has been primary source to improve Wang’s attack

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