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Some one sent this to me and I have tried to figure it ouut on my own. But have not been successful. Can you help figure out this, he said it was in MD5... 1ce67f05968d51656eb71f13368f0b2d

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    Oh my GOD! holy F! deep breathing right now! Thank you for helping me out. Yeah, he might be a little, big nerd but he is pretty wonderful...but it's kinda soon..lol OMG
    – MBC
    Feb 29, 2016 at 20:17
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    Perhaps he agrees, and thus the addition of "...one day."
    – Xander
    Feb 29, 2016 at 20:23
  • Did Biff send it to you? Feb 29, 2016 at 21:09
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    I agree with @Xander, based on the wording I wouldn't consider it to be a formal marriage proposal. Especially if he did not expect the secret message to be so easily revealed!
    – Kevin K
    Feb 29, 2016 at 21:27

1 Answer 1

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MD5 is not encryption, it is hashing. Not the same thing at all.

Otherwise, congratulations ! Whoever sends that to you is proposing marriage:

$ printf "You will be my wife one day" | md5sum
1ce67f05968d51656eb71f13368f0b2d  -

(Take care before answering "yes": he looks like a big nerd.)


Edit: the interesting part is of course how I found the source. I just looked it up on Google. The Web + Google makes for a rather good table of precomputed hash values.

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    There may be infinite number of phrases with this hash, is not it?:)
    – user996142
    Feb 29, 2016 at 19:31
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    Not infinite in that the MD5 input is formally limited to 2^61 bytes or so, but yeah, a pretty high number. However, finding another one that matches that one could be quite challenging. Even computing a full-ASCII collision (collisions between two messages that consist only of ASCII characters) would be article-worthy; two meaningful colliding ASCII messages would be even better.
    – Tom Leek
    Feb 29, 2016 at 19:34
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    The most impressive bit in this is that the guy used an online tool to hash it instead of some offline method. This way, that exact hash is added to rainbow tables all over the world eventually. So it would become Googlable. He should have made it more romantic by including the girl's name, though.
    – Adi
    Feb 29, 2016 at 20:22
  • @Adi if he included the name it could potentially expose her. Also, maybe he was not the one that hashed it in the first place, and just found it.
    – Mindwin
    Feb 29, 2016 at 20:27
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    Known collision attacks on MD5 use differential paths that work mostly on the high-order bits of input words (because these bits are linear in 32-bit additions) so we do not have cheap methods to compute ASCII-compatible MD5 collisions. Or if there is, I want to see it !
    – Tom Leek
    Feb 29, 2016 at 20:38

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