
Using blockchain for identity management is mostly ridiculous - detstrat
https://blog.xot.nl/2017/09/06/blockcerts-using-blokchain-for-identity-management-is-mostly-ridiculous/
======
kimhd
The original article was based on fundamental misunderstandings of Blockcerts,
but the follow-up Blockcerts community discussion (including the article's
author) was productive:

[http://community.blockcerts.org/t/response-to-blockchain-
blo...](http://community.blockcerts.org/t/response-to-blockchain-blockcerts-
critiques-from-privacy-researcher/308)

~~~
detstrat
Including the response of JHH in the comments again.

------
noddy1
Im a "blockchain-for-x" skeptic, but I disagree with this article.

A timestamped, immutable blockchain would be useful for reviewing credentials
from 3rd world countries where qualifications/experience/government
certification are all able to be bought. It wouldn't solve fraud, but it would
make it a lot harder to suddenly decide to fake a whole lot of credentials,
and would make it more obvious that a particular organization is corrupt and
therefore would incentivize not being corrupt.

The central question for whether blockchains are indicated for a particular
use case continues to be "does this require immutability, regulation
resistance, or cooperation across various regimes that don't trust each
other".

An example of useful blockchain identity would be in refugee
verification/processing: \- people in 3rd world countries scan a fingerprint
and hash an encrypted version on the blockchain when young \- annually update
information about themselves onto the blockchain including info about families
\- 10 years down the line they have an excellent record of who they are, who
their family is, what their situation is, and they become far more credible
when it comes to identity verification that relying on documentation from a
long-toppled government

~~~
xdeqx366
You're basically specifiying PKI, not anything to do with Blockchain.

If you truly want the timestamps to "lock in" the time of a transaction
without trusting either party, a hash-commitment could be used, akin to
[https://opentimestamps.org/](https://opentimestamps.org/).

~~~
subway
A blockchain seems like a very reasonable way to provide a distributed
immutable log of actions that take place within a PKI infrastructure. It even
adds the ability for 3rd party auditors to participate in the system in a
real-time manner.

You might even extend it, so that instead of it being PKI with a blockchain
transport, to something more akin to Kerberos with a blockchain transport --
every attempt, successful or not, to access a resource could be immutably
logged, and access could be granted by the targeted resource only once the
authorization message has been committed to the blockchain (and therefore
approved by auditors)

~~~
captn3m0
Cert Transparency is an effort on that front: [https://www.certificate-
transparency.org/faq](https://www.certificate-transparency.org/faq), and it
works without a blockchain.

~~~
subway
Cert Transparency depends on our benevolent lord Google to maintain the
integrity of the log. Using a blockchain pushes that trust model out such that
it's distributed across multiple actors.

There's nothing wrong with CT -- it's a great step in the right direction.
There's also nothing wrong with exploring distributed immutable logging.

------
TylerE
Using blockchain for $x is (mostly) ridiculous

~~~
Kinnard
Today. But tomorrow? And who will be well-positioned then?

~~~
KirinDave
... Why? Why would a bad choice of algorithms and specious "security"
guarantees be a better choice tomorrow?

------
theyblinked
The architect of the Blockcerts system replies to this article here:

[http://community.blockcerts.org/t/response-to-blockchain-
blo...](http://community.blockcerts.org/t/response-to-blockchain-blockcerts-
critiques-from-privacy-researcher/308)

“It’s interesting that he focuses on blockchain for identity management, which
Blockcerts doesn’t even do.

However, DIDs, which can improve the ability of individuals to own/control
their identity, will feature blockchain-based method specs.”

------
thinkloop
I don't understand what the "privacy nightmare" is that the author describes:

> The credential itself is signed by the issuer, which makes it authentic and
> binds it its owner. In itself this does not appear to create a big privacy
> problem, compared to standard PKI certificates. However, one of the keynotes
> suggested that also uses, i.e. verifications, of credentials could be logged
> on the blockchain. That information could subsequently be used to make e.g.
> policy decisions on employability: which academic credentials lead to the
> best employment opportunities? This is a privacy nightmare.

And is the author suggesting simply checking credentials against a centralized
authority:

> All you need is that each issuer keeps a list of all issued credentials in a
> _local_ immutable record (using a simple hash-chain, for example) against
> which a verifier can check the status of a credential.

My comprehension of this article is low.

~~~
DennisP
> verifications, of credentials could be logged on the blockchain

And how would that work anyway? He just finished saying that everything on the
chain is public. You don't have to issue a transaction to read it, you can
just read the public information off your local node.

------
Buttes
>what would happen to all credentials once issued to some blockchain, if that
blockchain ceases to operate? The raw blockchain data is of course still
available and maintains its blockchain structure. Yet the integrity-preserving
features of the blockchain disappear as soon as it is no longer actively used.

I'm not sure this is true. Info about the blockchain wouldn't evaporate
instantly, it'd be easy to get the legit genesis block header and chain
height, wouldn't it require a lot of "work" to produce a convincing
counterfeit chain?

~~~
KirinDave
No. It'd require only slightly more work than the cost of generating a block
at that time, to generate a new plausible block altered arbitrarily.

The power of the "head" of the blockchain is the human consensus around it. It
is otherwise unprivileged.

~~~
DennisP
As with any transaction on a proof of work chain, the more work there is
layered on top of the item in question, the more confidence you can have. Even
if you don't know that someone's presenting you with a truncated chain, you
can still see that their credential is at the end of it, and know that they
could have cheaply faked it.

Proof of stake would require more human consensus but proof of work is
measurably expensive to produce.

~~~
KirinDave
> As with any transaction on a proof of work chain,

Only _active_ proof of work chains. Discontinued chains have no active,
competitive consensus and may be arbitrarily rewritten by attackers since
there is no competition at any historical point in the chain for a quick
mining operation and there is no consensus about the head of the chain.

If there are additional credentials and signatures embedded in the chain
(there need not be) then THESE are the trust tokens that have value after the
chain is discontinued.

Blockchains only offer one thing: human consensus when humans are not
necessarily inclined to reach it. That is what a PoW or PoS blockchain
algorithm for cryptocurrency is trying to guarantee.

~~~
DennisP
You can still measure the total amount of hashpower applied. Someone could add
arbitrarily many blocks but you can calculate how much it cost for them to do
it.

~~~
KirinDave
So? Without competition for time it's pretty easy to make quite long
blockchains.

It's the competition for time that makes the mining reliable right now.

~~~
psyc
I'm struggling to pinpoint where you two are talking past each other. "Length"
in the context of a blockchain refers quite specifically to the amount of
actual work. So "easy" to make "long" chain, seems like a straightforward
contradiction.

~~~
KirinDave
The amount of calculation necessary to add a block to the chain is not
undoable by someone with modest resources.

What's difficult is doing it as quickly as Bitcoin miners with specialized
hardware and big energy footprints.

You can make a new blockchain add got Bitcoin today on EC2 without
overwhelming expense. Even 30 of them. No problem! It'd take too long to be
practical for mining, but that's not the senario we are discussing

Would you beat other miners in? Absolutely not. But the scenario being
discussed here is the historical value of blockchains once there is no mining
pool racing on them.

And the answer both the article and I propose is: "It is almost none" compared
to the other cryptographic tokens. Especially if the chain isn't receiving
constant, small commits.

------
tenaciousDaniel
Using it _today_ for identity management is ridiculous. It's a brand new
technology and will take time to fully develop.

~~~
imustbeevil
Using brand new kind of liberally here.

The idea of a blockchain is more than 20 years old, with the first popular
implementation, Bitcoin, being 9 years old.

That's the same year the iPhone 3G came out. So if you want to argue "brand
new" that's where you've got to start.

[https://en.wikipedia.org/wiki/Blockchain](https://en.wikipedia.org/wiki/Blockchain)

[https://en.wikipedia.org/wiki/IPhone_3G](https://en.wikipedia.org/wiki/IPhone_3G)

------
arisAlexis
Actually I didn't read any concrete arguments against. Blockchain ceasing to
operate? That it's an overkill? Hm.

------
kusmi
Doesn't e-estonia use block chain for identity?

~~~
dmitrygr
no. They simply use digital signatures. Blockchain is as needed here as a
bicycle is needed by a fish.

------
mistermumble
Worthwhile article. But please correct the typo in the HN headline. (Even
though it is in the original, it grates).

