1 / 9

SHA (secure hash algorithm)

SHA (secure hash algorithm). Jen-Chang Liu, 2005 Adapted from l ecture slides by Lawrie Brown. History of SHA. SHA: secure hash algorithm Developed by National Institute of Standard and Technology (NIST) Based on the MD4 FIPS 180 in 1993

april-steele
Download Presentation

SHA (secure hash algorithm)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SHA (secure hash algorithm) Jen-Chang Liu, 2005 Adapted from lecture slides by Lawrie Brown

  2. History of SHA • SHA: secure hash algorithm • Developed by National Institute of Standard and Technology (NIST) • Based on the MD4 • FIPS 180 in 1993 • SHA-1: revised SHA, FIPS 180-1 in 1995, also RFC 3174

  3. Secure hash algorithm (SHA) • SHA logic 512-bit block 160 160 160 160 SHA SHA SHA SHA 160-bit digest

  4. SHA round for 512-bit block 5 個 32- bit words 4 different functions: Totally 80 steps

  5. Elementary SHA operation 32 bits 32 bits 32 bits 32 bits 32 bits From 512-bit input block Circular left shift 5 bits Fixed constant

  6. SHA bitswise functions

  7. W[0-79] from input 512-bit block • W[0-79]

  8. Security of SHA • Against brute-force attack • Produce any message having a given SHA digest is on the order of 2160 • Against cryptanalysis • No known attacks • Speed • Logic operation & addition modulo 232 • Fast on 32-bit architecture • Simple to implement

  9. Improvement to SHA • Comparison of SHA-x

More Related