Lecture 21: SHA-1 Hash Function by Christof Paar

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  • Опубліковано 28 вер 2024
  • For slides, a problem set and more on learning cryptography, visit www.crypto-textbook.com

КОМЕНТАРІ • 39

  • @jimperkins9661
    @jimperkins9661 Рік тому +1

    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).

  • @kommxxx
    @kommxxx 8 років тому +5

    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.

  • @ben5235
    @ben5235 7 років тому +9

    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!

  • @martinpattara
    @martinpattara 7 років тому +3

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

  • @1UniverseGames
    @1UniverseGames 3 роки тому

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

  • @ahmedmuhammed6905
    @ahmedmuhammed6905 2 роки тому

    It is really enjoyable to watch it

  • @Zelmann1
    @Zelmann1 7 років тому

    Best cryptography lectures :)

  • @gibsons4188
    @gibsons4188 7 років тому

    'Heres a .vbs to start your sha-1 hash dictionary
    'records input word and output sha-1 hash ie. Cryptography, b804ec5a0d83d19d8db908572f51196505d09f98
    '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 = CreateObject("System.Text.UTF8Encoding")
    Set enc = CreateObject("System.Security.Cryptography.SHA1CryptoServiceProvider")
    bytes = asc.GetBytes_4(instr)
    bytes = enc.ComputeHash_2((bytes))
    outstr = ""
    Set FS = CreateObject("Scripting.FileSystemObject")
    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

    • @aethrya
      @aethrya Рік тому

      whatever you say nerd

  • @saurabhparekh884
    @saurabhparekh884 9 років тому

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

  • @fikrikabakcha7210
    @fikrikabakcha7210 9 років тому

    Vielen Dank! Grüße aus Karlsruhe!

  • @m.dvenkatesh7718
    @m.dvenkatesh7718 6 років тому

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

    • @douwehuysmans5959
      @douwehuysmans5959 4 роки тому +1

      I know this is 2 years later but the reason is that information gets lost.
      You AND two bits A and B, and you get a 0 you only know that A and B were not both 1, but you don't know if A was 0 or B was 0 or both were 0. This makes it hard to reverse engineer

  • @saurabhparekh3927
    @saurabhparekh3927 9 років тому

    are there any lectures on SHA-512

    • @introductiontocryptography4223
      @introductiontocryptography4223  9 років тому +10

      +Saurabh Parekh Unfortunately not. However, SHA-512 is not that different from SHA-1. Once you understood SHA-1, SHA-512 shouldn't too difficult. (Note that SHA-3 is completely different from SHA-1 und -2). Cheers, christof

    • @NirantK
      @NirantK 8 років тому

      You can also refer Foruzan's Cryptography book for SHA-12. It has detailed explaination of each round and so on.

    • @sathyamurthisadhasivan6275
      @sathyamurthisadhasivan6275 8 років тому

      Now, coming to SHA-3, do you plan to offer a video lecture on it please?
      It is quite convoluted and all I am seeing is the push for its adoption for most of the future hash designs...

    • @iurnah
      @iurnah 6 років тому

      He actually did the SHA-3 what's a amazing professor, ua-cam.com/video/JWskjzgiIa4/v-deo.html

  • @MrPinder91
    @MrPinder91 7 років тому

    Please make a video regarding sha-3

  • @sandyhardstone722
    @sandyhardstone722 5 років тому +8

    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

    • @danielcontreras3045
      @danielcontreras3045 5 років тому +2

      the best observation, the teacher was in a hurry xD

    • @migelbuscador6919
      @migelbuscador6919 3 роки тому +3

      I wish I had read your comment earlier, I tried to reprogram this algorithm on my own, but I didnt work until I found this tiny mistake...

    • @bitte929
      @bitte929 9 місяців тому

      Even I was confused with this, Thanks a lot

  • @dpraajz
    @dpraajz 4 роки тому +10

    19:00 SHA-1

  • @ahmedmamdouh3964
    @ahmedmamdouh3964 9 місяців тому +1

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

  • @michalbotor
    @michalbotor 4 роки тому +2

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

  • @spdx1
    @spdx1 6 років тому +3

    The door was closed...

  • @olegmenyaylenko3449
    @olegmenyaylenko3449 4 роки тому +1

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

  • @LATIFAHMOHDNOR-zy1mq
    @LATIFAHMOHDNOR-zy1mq День тому

    Page 545
    hash total (Comp) A meaningless number generated from a coded data item or its key. See check sum, hashing.

    • @LATIFAHMOHDNOR-zy1mq
      @LATIFAHMOHDNOR-zy1mq День тому

      hashing (Comp) Generating hash totals to associate with items of data. The numbers are used as index numbers or storage addresses for the data.

  • @__angle
    @__angle Рік тому

    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 !!!

  • @ralph17p
    @ralph17p 2 роки тому

    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.

  • @mr.unknown4124
    @mr.unknown4124 Місяць тому

    MIND BLOWING

  • @Maiiepmaidiep2610
    @Maiiepmaidiep2610 7 років тому +10

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

  • @1UniverseGames
    @1UniverseGames 3 роки тому

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

  • @prashantdhumal2483
    @prashantdhumal2483 6 років тому

    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

    • @jacksnow1381
      @jacksnow1381 6 років тому

      Prashant Dhumal
      its secure for using in cryptographic uses like finger print and using in digital signature algorithms and ... . it has 4 requirements professor Paar mentioned in lecture 20. there are other hash functions which are not secure and doesn't have those requirements.

  • @imraniqbal4176
    @imraniqbal4176 Рік тому

    Nice