4 ms·

One thing I was trying to find. Is it possible to completely erase things from history? Because if not, the first time someone uploads something illegal to you

One thing I was trying to find. Is it possible to completely erase things from history? Because if not, the first time someone uploads something illegal to your decentralized wikipedia and it gets into the block chain, you are in trouble.

verdverm 7y ago
I have yet to see this issue addressed in a meaningful way.
- theK 7y ago
  I am very curious about this ideology. The whole world seems to see indelibility of data as a problem in this context. Yet immutability is seen as a generally good thing for a lot of other software cases. Further we cannot manipulate past events and there even is something about repeating history when you don’t know it. So why would we really want to delete past data? From this standpoint wouldn’t deleting data be similar to trying to cover up the past? Sure we might also try to label it “humankind’s childish try to assert itself over the unstoppable arrow of time” but that is just too Freudian to me. Is there some big idea I’m missing that explains the favoring of the “mutable past” view?
  - hk__2 7y ago
    > So why would we really want to delete past data? From this standpoint wouldn’t deleting data be similar to trying to cover up the past? This assumes that data is always true and accurate, which is not always the case. Say Bob was convicted for pedophilia but a couple months after the charge was retracted because it was an error. Now Bob can’t find a job because “the data” says he’s a pedophile, even if he’s not.
    - 04091948 7y ago
      and why can't bob find a job even if he was a pedophile or a murderer or whatever? why is extrajudicial punishment allowed?
      - x0137294744532 7y ago
        > why is extrajudicial punishment allowed? In some cases it is common sense. For instance: a pedophile shouldn't be allowed to be a school teacher.
        04091948 7y ago
        in that case, there should be a court order that prevents them from exercising such occupations.
        verdverm 7y ago
        Even if, there is still human bias. What if someone posted false claims about you? Would you like recourse in that event?
  - nradov 7y ago
    What you're missing is that in some domains like healthcare there are legal compliance requirements to delete past data in certain circumstances. If false or embarrassing or misattributed data ends up in my medical record I want it completely removed, not just marked as outdated. This isn't just ideology, it's a fundamental matter of patient privacy.
  - _jal 7y ago
    > Is there some big idea I’m missing that explains the favoring of the “mutable past” view? It is called law. There are lots of laws that govern circumstances under which data must be destroyed, and others that make certain data illegal to possess. You can argue that they're bad laws, and I'd agree that some of them are. But whatever you think of them, ignore them at your peril.
  - verdverm 7y ago
    HIPAA, GDPR, CCPA, Right to be Forgotten, DMCA The ideology is law, most blockchains as is do not comply with law. So the are effectively unusable in practice (generally speaking too)
  - CJefferson 7y ago
    I think this is a case where "Think of the children" is the right answer. Someone uploads pictures of a child being violently sexually abused to a blockchain. It is my honest opinion the majority of people would not want to continue distributing those photos. It is certainly the law of many countries that it is illegal to distribute such pictures.
  - blackandblue 7y ago
    well there was that new york time podcast on child abuse and how the internet made things exponentially worse... that was quite a big moment for me about being able to remove online data. yes, we need to be able to erase stuff from the internet.
- steve76 7y ago
  Use peer to peer, like a list of well known dat archives, as a data source for a static site generator. In-app peers listen to one another like web sockets. They write what they want and the site sources the best.
trevyn 7y ago
How does Bitcoin handle this?
- dboreham 7y ago
  It doesn't.
iwalton3 7y ago
This is difficult to handle without some centralized authority. One example I can think of is Aether [1], which has a non-decentralized blacklist for illegal content [2] that they can use to handle these instances. It could also be possible to broadcast some kind of signed take-down message that could be propagated through all of the nodes. If I remember right, Aether said that the centrally hosted json file was needed for legal compliance though. [1] https://getaether.net/ https://getaether.net/ [2] https://static.getaether.net/Badlist/Latest/badlist.json https://static.getaether.net/Badlist/Latest/badlist.json
- fwip 7y ago
  Decentralized systems that use append-only logs (which includes but is not limited to blockchain stuff) need the equivalent of a 'git rebase' to purge history. Like lwalton says, this is very difficult to do without centralizing authority, as a rebase is a fork, and so you need the whole community to rebase/fork simultaneously. This is a big deal if all data is in the same place. One approach is to break these logs apart, e.g. per-user, like Cabal does it. Instead of replicating one giant log, you replicate many small logs. As a user, you can choose which logs you want to store, replicate, and which contribute to your materialized view. Or, you can delegate this work to a moderator you trust, who in turn may subscribe to other moderators or blacklists to inform their moderation. In this way, there's no centralized authority - everyone is their own authority. Writing the user-facing moderation tools is important work, but is a relatively well-understood problem.
  - pfraze 7y ago
    Generally speaking, this is the right call - though you don't necessarily need to rebase the whole log. The hypercore logs that Cabal uses can partially sync. You can choose not to sync certain chunks without losing verifiability; all that would persist is the hash of that chunk.
api 7y ago
I've heard this called a "pool pissing attack," as in peeing in the swimming pool, and it's already been done to some block chains, which contain CP and other illegal stuff. One mitigation I've used in one project is to hash records by hashing hashes of their fields, permitting record fields to be selectively deleted from storage (e.g. by a blacklist) without breaking data structure validation capability.

verdverm 7y ago

I have yet to see this issue addressed in a meaningful way.

theK 7y ago
I am very curious about this ideology. The whole world seems to see indelibility of data as a problem in this context. Yet immutability is seen as a generally good thing for a lot of other software cases. Further we cannot manipulate past events and there even is something about repeating history when you don’t know it. So why would we really want to delete past data? From this standpoint wouldn’t deleting data be similar to trying to cover up the past? Sure we might also try to label it “humankind’s childish try to assert itself over the unstoppable arrow of time” but that is just too Freudian to me. Is there some big idea I’m missing that explains the favoring of the “mutable past” view?
- hk__2 7y ago
  > So why would we really want to delete past data? From this standpoint wouldn’t deleting data be similar to trying to cover up the past? This assumes that data is always true and accurate, which is not always the case. Say Bob was convicted for pedophilia but a couple months after the charge was retracted because it was an error. Now Bob can’t find a job because “the data” says he’s a pedophile, even if he’s not.
  - 04091948 7y ago
    and why can't bob find a job even if he was a pedophile or a murderer or whatever? why is extrajudicial punishment allowed?
    - x0137294744532 7y ago
      > why is extrajudicial punishment allowed? In some cases it is common sense. For instance: a pedophile shouldn't be allowed to be a school teacher.
      - 04091948 7y ago
        in that case, there should be a court order that prevents them from exercising such occupations.
        verdverm 7y ago
        Even if, there is still human bias. What if someone posted false claims about you? Would you like recourse in that event?
- nradov 7y ago
  What you're missing is that in some domains like healthcare there are legal compliance requirements to delete past data in certain circumstances. If false or embarrassing or misattributed data ends up in my medical record I want it completely removed, not just marked as outdated. This isn't just ideology, it's a fundamental matter of patient privacy.
- _jal 7y ago
  > Is there some big idea I’m missing that explains the favoring of the “mutable past” view? It is called law. There are lots of laws that govern circumstances under which data must be destroyed, and others that make certain data illegal to possess. You can argue that they're bad laws, and I'd agree that some of them are. But whatever you think of them, ignore them at your peril.
- verdverm 7y ago
  HIPAA, GDPR, CCPA, Right to be Forgotten, DMCA The ideology is law, most blockchains as is do not comply with law. So the are effectively unusable in practice (generally speaking too)
- CJefferson 7y ago
  I think this is a case where "Think of the children" is the right answer. Someone uploads pictures of a child being violently sexually abused to a blockchain. It is my honest opinion the majority of people would not want to continue distributing those photos. It is certainly the law of many countries that it is illegal to distribute such pictures.
- blackandblue 7y ago
  well there was that new york time podcast on child abuse and how the internet made things exponentially worse... that was quite a big moment for me about being able to remove online data. yes, we need to be able to erase stuff from the internet.
steve76 7y ago
Use peer to peer, like a list of well known dat archives, as a data source for a static site generator. In-app peers listen to one another like web sockets. They write what they want and the site sources the best.

trevyn 7y ago

How does Bitcoin handle this?

dboreham 7y ago
It doesn't.

iwalton3 7y ago

This is difficult to handle without some centralized authority. One example I can think of is Aether [1], which has a non-decentralized blacklist for illegal content [2] that they can use to handle these instances. It could also be possible to broadcast some kind of signed take-down message that could be propagated through all of the nodes. If I remember right, Aether said that the centrally hosted json file was needed for legal compliance though. [1] https://getaether.net/ https://getaether.net/ [2] https://static.getaether.net/Badlist/Latest/badlist.json https://static.getaether.net/Badlist/Latest/badlist.json

fwip 7y ago
Decentralized systems that use append-only logs (which includes but is not limited to blockchain stuff) need the equivalent of a 'git rebase' to purge history. Like lwalton says, this is very difficult to do without centralizing authority, as a rebase is a fork, and so you need the whole community to rebase/fork simultaneously. This is a big deal if all data is in the same place. One approach is to break these logs apart, e.g. per-user, like Cabal does it. Instead of replicating one giant log, you replicate many small logs. As a user, you can choose which logs you want to store, replicate, and which contribute to your materialized view. Or, you can delegate this work to a moderator you trust, who in turn may subscribe to other moderators or blacklists to inform their moderation. In this way, there's no centralized authority - everyone is their own authority. Writing the user-facing moderation tools is important work, but is a relatively well-understood problem.
- pfraze 7y ago
  Generally speaking, this is the right call - though you don't necessarily need to rebase the whole log. The hypercore logs that Cabal uses can partially sync. You can choose not to sync certain chunks without losing verifiability; all that would persist is the hash of that chunk.

api 7y ago

I've heard this called a "pool pissing attack," as in peeing in the swimming pool, and it's already been done to some block chains, which contain CP and other illegal stuff. One mitigation I've used in one project is to hash records by hashing hashes of their fields, permitting record fields to be selectively deleted from storage (e.g. by a blacklist) without breaking data structure validation capability.