…and 20G that needs to be replicated to tons of nodes if it should be really decentralized.
16-28 bytes seems extremely understated, I think it could easily be off by orders of magnitude.
Comment on Is the blockchain an interesting innovation, aside from cryptocurrencies ?
Ajen@sh.itjust.works 1 year agoSomething about this comment didn’t seem right to me, so I did some quick math:
There are approx 144,000,000 homes (incl apartments, etc) in the US. www.census.gov/quickfacts/fact/table/…/VET605221
Assuming every home is sold 5 times on average, that’s 720,000,000 sale records/deeds.
Existing blockchain implementations use IDs that are around 32 bits, or 4 bytes.
A “home sales record” or deed on the blockchain needs to include the buyer and the time/date of sale (8 bytes), along with a cryptographic signature (4-16 bytes). The seller’s identity doesn’t need to be included because it’s always doing to be the previous owner.
So each record is 16-28 bytes, and there are 720,000,000 records. If we go with 28bytes, it would take about 20GB to store all of the deeds for the US. A 500GB hard drive costs $20.
netvor@lemmy.world 1 year ago
Ajen@sh.itjust.works 1 year ago
What do you think I’m missing in my estimate? Do you have any experience in CS?
DogMuffins@discuss.tchncs.de 1 year ago
You’re just talking about ownership of a title right?
A deed contains a lot more information than the owner. Mine is 4 pages long. Contains a map of the street, various easements, et cetera.
Ajen@sh.itjust.works 1 year ago
Yeah, but that kind of data would be better in an auxiliary database. There’s no reason to include it in the blockchain.
Valmond4@lemmy.mindoki.com 1 year ago
You forget that the blockchain is all about not trusting some middle-man/site, so you need to stock that blockchain yourself, everyone needs to stock that blockchain.
So multiply not only the cost, but also the ecological impact just buying all those drives.
And that’s only for *US" housing (I didn’t get the timeframe you used to calculate it, is it for like year 2050? Old data stays forever.).
BTW found the guy buying 0.5TB Hard drives ;-)
Ajen@sh.itjust.works 1 year ago
Yes, everyone would need a copy of the 10s-of-GB blockchain. That’s a fraction of the amount of space a single computer game would use, does that seem unreasonable/impractical to you?
And I buy used enterprise 2-3TB drives on eBay :) . I was going to use a 32GB flash drive for my example, but a 500GB HDD is the same price
Valmond4@lemmy.mindoki.com 1 year ago
Fair enough about the size.
Checked out eBay, there are some cheap 2-3Tb drives there! How does it pan out quality wise? I guess they sell them off like after 5 years of usage right?
Ajen@sh.itjust.works 1 year ago
Yeah, that’s my understanding. Tbh I don’t have a lot of experience with them yet, but I’m building an 8 disk RAID6 array and I decided to go with those used drives. 10 matching disks will be around $120, and I’ll have 2 extra drives so I can rebuild the array asap if a drive fails.