Lecture 21: SHA-1 Hash Function by Christof Paar

[sandyhardstone]

Correct me if I'm wrong but this is actually SHA-0. SHA-1 requires a circular shift to the left by 1 position of the "words", Wj (16<=j<=79).

[ben]

Fantastic lectures, professor Paar! Just want to thank you for the excellent effort you put into these! What you say at 55:00 is something all lecturers need to strive for!

[jimperkins]

This was the most informative and clear lecture of the series so far (going through in order). Professor Paar's accent and cadence are particularly engaging (he should consider radio or film if lecturing get too booooring (said in the Paar style/cadence/idiom) for him).

[ralphp]

Thank you! This series was instrumental in helping me pass my cryptography module at KCL. I'd read their stuff and come here to have it make sense. Then I went back and just made sure I knew their notation for the algorithms.

[martinpattara]

Thanks Professor .Does Sha1 specifies anything about IV (ie : h0 to be used when compressing x1 ) ?

[ahmedmamdouh]

SHA1: algorithm 21:40 (high level)
SHA1: rounds details 52:30
SHA1: word scheduler 1:11:57

[kommxxx]

Unfortunately there is a little mistake in the last formula for computing W_j: After XORing the four previously computed Ws one has to do a rotation to the left by one bit.

[__angle]

Thanks again for all this great stuff.
I would like to know where i could find explanation about the WHY (why we use those 4 constants why we use those 4 functions and why we shift the message like that). I imagine that there is a Mathematical reasoning behind those choices and i would really be interested to understand them. Thanks !!!

[UniverseGames]

Which software or tool.to analyze this collision, any could name it

[UniverseGames]

Any programming explanation of these lessons. Or any resources to learn programming for these lecture. Any helps

[michalbotor]

it's funny when you watch it online. what delay? you're right on my schedule. :D

[Maiiepmaidiep]

SHA-1 is now dead but this lecture is still valuable for learning purpose

[prashantdhumal]

Hi
Does SHA means secure hash ? if yes then where is the security comes from since we do not have secret value while generating SHA-1 hash

[saurabhparekh]

Thank you so much sir and your videos are really helpful thank you..!!

[gibsons]

'Heres a .vbs to start your sha-1 hash dictionary
'records input word and output sha-1 hash ie. Cryptography,
'thanks to the prof for making these videos public.

Option Explicit
Dim asc, enc, bytes, instr, outstr, pos, FS, FT
Const ForReading = 1, ForWriting = 2, ForAppending = 8

instr = Inputbox("Enter string to encrypt with SHA-1:", "")

Set asc =
Set enc =
bytes = asc.GetBytes_4(instr)
bytes = enc.ComputeHash_2((bytes))

outstr = ""

Set FS =
Set FT = FS.OpenTextFile("sha1.txt", ForAppending, True)

For pos = 1 To Lenb(bytes)
outstr = outstr & LCase(Right("0" & Hex(Ascb(Midb(bytes, pos, 1))), 2))
Next

FT.WriteLine(instr & ", " & outstr)
FT.Close

WScript.Echo instr & ", " & outstr & vbcrlf & "added to sha1.txt"
WScript.quit

[LATIFAHMOHDNOR-zymq]

Page 545


hash total (Comp) A meaningless number generated from a coded data item or its key. See check sum, hashing.

[olegmenyaylenko]

haha 3 years after the lecture, Google found the first SHA-1 collision

[m.dvenkatesh]

We know everything why it is difficult to reverse engineering ( i mean encryption in Bitcoin)