Dropping Hashes (2020)(kalzumeus.com)
kalzumeus.com
Dropping Hashes (2020)
https://www.kalzumeus.com/essays/dropping-hashes/
17 comments
Before hashes existed, it wasn't unusual for scientists in the 17th and 18th century to drop an anagram instead, to establish priority on a discovery before one was ready to fully explain it. For example, in 1676 Hooke published an article containing the string of letters "ceiiinosssttuv", which two years later he revealed to stand for "ut tension, sic vis", meaning "as the extension, so the force".
The word "timestamping" doesn't appear anywhere in the blog post so here's a related link: https://en.wikipedia.org/wiki/Trusted_timestamping
And for historical trivia, the oldest blockchain via printed ads in NYTimes: https://www.vice.com/en/article/j5nzx4/what-was-the-first-bl...
And you have other timestamping services like GlobalSign and embedding data into bitcoin blockchain.
And for historical trivia, the oldest blockchain via printed ads in NYTimes: https://www.vice.com/en/article/j5nzx4/what-was-the-first-bl...
And you have other timestamping services like GlobalSign and embedding data into bitcoin blockchain.
Having the hash at any given moment doesn’t prove that I had the file at that moment, but rather that someone had the file, generated the hash, and I have the hash. (This is obvious to most readers on HN, but might not be obvious to casual or non-specialist readers of Patrick’s article.)
The hashed file itself might contain your name. Or you could just publish a signature (a hash encrypted with your private key such that anybody with the public key can recover the hash) instead.
The really interesting part here is that a hash is a core building block for proving a priori knowledge.
The really interesting part here is that a hash is a core building block for proving a priori knowledge.
As I understand him, there exists some reddit/twitter/mailinglist/other channel where people post messages like this:
I am [Identity] and I claim hash [hex digits]
[9 months pass]
My claimed hash corresponds to [link], which proves I could have hacked [target] 9 months ago.
Robert O'Callahan hashed some thoughts about Firefox that he revealed many years later:
https://robert.ocallahan.org/2018/01/ancient-browser-wars-hi...
https://robert.ocallahan.org/2018/01/ancient-browser-wars-hi...
In the past Patrick has used Twitter https://twitter.com/patio11/status/1252585766489899010?lang=...
I think this same technology is the basis for some cryptocurrency contracts which monetize claims on future events (prediction markets). The prediction is hashed and the topic is stored in a smart contract. Then, should the prediction be true, later the future-teller benefits from the counterparties' commitment to the opposite side of the contract.
Is this being posted because of this?
The Working Group's White paper on Japan and covid-19
https://www.kalzumeus.com/covid19-japan-white-paper/
Any updates on this paper and the eponymous group?
The Working Group's White paper on Japan and covid-19
https://www.kalzumeus.com/covid19-japan-white-paper/
Any updates on this paper and the eponymous group?
ipfs is great for this as it eliminates the manual file publishing and hash verification steps. you can publish the ipfs hash and when you want to disclose publicly, you can start providing the data on ipfs and everyone can download the file that belongs to the hash.
Same with Torrents as well.
The usage of "dropping" is confusing here, and implies "stopping the usage of". If the author did not use a rare definition of "dropping" the post would have no purpose.
https://www.merriam-webster.com/dictionary/drop
> transitive verb
> 3 a : to utter or mention in a casual way
> // drop a suggestion
> // drop names
Doesn't seem that rare to me, but that's just my opinion. I viewed it somewhat similar to "name dropping" after reading the OP.
> transitive verb
> 3 a : to utter or mention in a casual way
> // drop a suggestion
> // drop names
Doesn't seem that rare to me, but that's just my opinion. I viewed it somewhat similar to "name dropping" after reading the OP.
In this context dropping means "leaving behind", as in "I dropped my water bottle in a trash can when I finished it." The author did not invent this terminology. He is explaining it to a wider audience.
Sorry if I misunderstood you, but I don't believe the author is advocating for this particular use of "dropping" to become mainstream. The author is explaining what "dropping a hash" means precisely because it is not widely understood. It's basically a term of art, not something created by the author.
Given the hash, it may be possible to guess the contents of the file. A safer way:
key=$(cat /dev/urandom | base64 | head -c 32)
printf $key | b3sum --keyed secret.txt
echo $keyFor a file significantly bigger than the size of the hash, it's not possible to reverse, since there are many such files that would match the hash. See: https://en.wikipedia.org/wiki/Pigeonhole_principle