Your SlideShare is downloading. ×
0
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Cryptography Ashik
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Cryptography Ashik

713

Published on

List cryptographic hash algorithms and list their applications. MD5 hash algorithm Description.

List cryptographic hash algorithms and list their applications. MD5 hash algorithm Description.

Published in: Education, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
713
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
25
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Welcome<br />Presentation on<br />Cryptography & Information Security<br />
  • 2. Topic<br />5<br />List cryptographic hash algorithms and list their applications. Discuss MD5 hash algorithm or any other hash algorithm in detail.<br />Submitted By:<br />Muhammad AshikIqbal<br />M.Sc. in CSE<br />ID: 092-25-127<br />DIU<br />ashik.email@gmail.com<br />http://ashikiqbal.blogspot.com<br />
  • 3. Cryptographic Hash Algorithms<br />
  • 4. List of Hash Algorithms<br />
  • 5. Applications of Hash Algorithms<br />Used Alone<br />File integrity verification<br />Public key fingerprint<br />Password storage<br />Combined with encryption functions<br />
  • 6. MD5<br />Message-Digest algorithm 5<br />
  • 7. MD5<br />Designed by Ronald Rivest in 1991 and replaces an earlier hash function MD4<br />MD5 is a widely used cryptographic hash function<br />128-bit hash function<br />Uses 512 bit blocks<br />Uses 128-bit keys or states<br />The 128-bit key is split into 4 sub-keys of 32 bits each<br />Four rounds are used to produce the hash<br />In each round addition, XOR, AND, OR, rotation are used<br />
  • 8. MD5 Example<br />hello<br />5d41402abc4b2a76b9719d911017c592<br />
  • 9. MD5 Algorithms<br />2. Append length (64bits)<br />1. Append padding bits<br />(to 448 mod 512)<br />3. Initialize MD buffer<br />Word A = 01 23 45 67<br />Word B = 89 AB CD EF<br />Word C = FE DC BA 98<br />Word D = 76 54 32 10<br />
  • 10. MD5 Algorithms<br />F(X,Y,Z) = (X ∧ Y) ∨ (¬X ∧ Z)<br />G(X,Y,Z) = (X ∧ Z) ∨ (Y ∧ ¬Z)<br />H(X,Y,Z) = X ⊕ Y ⊕ Z<br />I(X,Y,Z) = Y ⊕ (X ∨ ¬Z)<br />Round 0: Steps 0 to 15<br />Round 1: Steps 16 to 31<br />Round 2: Steps 32 to 47<br />16 steps<br />Round 4: Steps 47 to 63<br />X[k] = M [q*16+k] (32 bit)<br />Constructed from sine function<br />
  • 11. MD5 Applications<br />MD5 has been employed in a wide variety of security applications and is also commonly used to check the integrity of files<br />Used in the software world to provide some assurance that a transferred file has arrived intact<br />Unix-based operating systems include MD5 sum utilities in their distribution packages<br />MD5 can provide error-checking functionality<br />It recognizes corrupt or incomplete download, which becomes more likely when downloading larger files<br />Widely used to store passwords after adding salt<br />
  • 12. MD5 Attack History<br />Dobbertin “almost” able to break MD5 using his MD4 attack in 1996<br />Showed that MD5 might be at risk<br />In 2004, Wang published one MD5 collision<br />No explanation of method was given<br />Based on one collision, Wang’s method was reverse engineered by Australian team<br />Ironically, this reverse engineering work has been primary source to improve Wang’s attack<br />
  • 13. Thank You<br />

×