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Comment by mSparks | Hacker News Reader

I see a lot of talk and little substance.

"You can have 128bit security with a 4 digit pin"....

No, No you can't. A 4 digit pin is 14 bit security. Any system is only as secure as its weakest link.

It's not a password it's a pin... Dear god, how have we not got past this yet.

While it's good to see an acceptance that iot is fundamentally unworkable on current infrastructure. I am a long way from being convinced this will be it's saviour.

EDIT:Furthermore: https://github.com/apache/incubator-milagro-crypto/blob/mast... /* Client and Server are issued secrets by DTA */

HELL NO.!.!.!.!.!

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I just learned about Milagro through this submission and only looked at a fraction of the docs but as someone who is not a cryptographer but put some effort into understanding pairing based cryptograph, I find the documentation excellent so far.

> No, No you can't. A 4 digit pin is 14 bit security. Any system is only as secure as its weakest link.

As far as I understand it, the PIN is used to secure a secret key for a 128bit security cryptosystem against key compromise. Like password protection on ssh keys, this provides stronger security than unprotected keys but I think this PIN is actually part of an interactive proof to protect against offline attacks.

The downside of Identity Based Encryption is that you need a master secret key (aside: I think we shoud find a less loaded term like root secret key) to derive the client secrets. The DTA is a way to avoid a single authority in posession of this root secret through secret sharing. Sharing in secret sharing is not copying but splitting into shares. I'm not yet sure if it works like I think it works but I think they use secure multiparty computation to use a shared root secret to derive shares of the client secrets that the clients combine to obtain their secret. That would be really awesome and about the best we can do before more powerful cryptography (functional encryption, fully homomorphic encryption etc.) becomes practical.

Exactly. its a password limited to 4 digits. And why? That gives you no more than 14 bit security even using a decent system like PBKDF2. Which i see no mention of.

secrets are just that - secret.

The only reason I know of that secrets need sharing is when you are running a key escrow system. Other than that secrets are locked away and used as rarely as possible. Never ever ever transmitted from machine to machine. Thats the key problem in crypto (pun intended). Stuff you transmit cant and wont stay secret.

Having read a little further, I think offline attacks are possible and 4 digits alone are useless today but that still does not weaken the security level. You need a key, whether you choose to use a password or not.

Correct me if I'm wrong but I don't see secret keys transmitted. The DTAs issue shares of the secret keys that are then combined. Also, transmitting secrets really is a motivating use case for cryptography.

they are creating a secret key by sending chunks of secret keys (with a mention of a blockchain database - not sure why). Or at least thats what i saw in the code comments.

secret in cryptography has a very special meaning - it refers to the part of the communication process you dont want visible.

encryption is actually mostly a solved problem. There are several good algorithms which are fine with no real problems.

The problems are all in establishing keys. For that there are currently only two choices in use. ecdh. which all the standard curves appear to be backdoored. and rsa, which the russians reckon they have broken.

the dta is just another key sharing scheme. needed. but not one that gives up on all the comsec we have gained so far.

do you not find it dishonest that they claim for example, that the uk government is using it already, but then it turns put it doesn't actually exist beyond a few lines of poc code.

"ecdh. which all the standard curves appear to be backdoored"

This is a pretty serious assertion to make as a throwaway comment. You're talking about the NIST sponsored constants suspected of being backdoored. ( https://en.wikipedia.org/wiki/Dual_EC_DRBG https://safecurves.cr.yp.to/ )

That's the reason Curve22519 (defined by djb, completely independent of any NIST involvement) has become popular and is being widely used as default in major ECDH implementations (https://en.wikipedia.org/wiki/Curve25519 ). As close to a "standard" as you'd find today that nobody believes to have known weaknesses or backdoors.

im mobile and traveling. tried to find my links to research but not in my mobile bookmarks. there is a great page somewhere that lists each curve --- edit you found it:

https://safecurves.cr.yp.to

for reference google (pdfs so cant get links from google mobile):

security dangers of nist curves

and also the reasoning behind the curve chosen for bitcoin.

so edit 2: just, yes. but note the safecurves quote " The core problem is that if you implement the standard curves, chances are you're doing it wrong:"

Please stop spreading FUD. The quote from safecurves you posted is actually describing the very reason safecurves exists in the first place. And it lists the curves that are safe to use.

"Most of these attacks would have been ruled out by better choices of curves that allow simple implementations to be secure implementations. This is the primary motivation for SafeCurves. The SafeCurves criteria are designed to ensure ECC security, not just ECDLP security."

Also you completely ignored them main part of my earlier comment. The actually widely adapted, curve25519 by djb (who's also the author of that safecurves page) with no currently known weaknesses (and needless to say, no backdoors either).

Confused.. Safecurves exists because all the standard curves appear to be backdoored. Curve25519 is not a standard curve. How is this FUD?

Curve25519 was first released by Daniel J. Bernstein in 2005,[7] but interest increased considerably after 2013 when it was discovered that the NSA had implemented a backdoor into Dual EC DRBG. While not directly related,[8] suspicious aspects of the NIST's P curve constants[9] led to concerns[10] that the NSA had chosen values that gave them an advantage in factoring[11] public keys.[12]

"Safecurves exists because all the standard curves appear to be backdoored. Curve25519 is not a standard curve.

This was your original stanza that I objected to:

"The problems are all in establishing keys. For that there are currently only two choices in use. ecdh. which all the standard curves appear to be backdoored. and rsa, which the russians reckon they have broken."

You were insinuating that basically there's no safe way to establish secrets (using some form of ecdh). While there absolutely is. Here's the list of open source packages using (safe) Curve25519 :

https://en.wikipedia.org/wiki/Curve25519

In 2014 OpenSSH[14] defaults to Curve25519-based ECDH.

Libraries[edit]

Libgcrypt[15]

libssh[14][16]

NaCl[17]

GnuTLS[18]

mbed TLS (formerly PolarSSL)[19]

wolfSSL[20]

Botan[21]

Libsodium[22]

OpenSSL since version 1.1.0[23]

What else do you want from a "standard"?

->You were insinuating that basically there's no safe way to establish secrets (using some form of ecdh). While there absolutely is.

I'm complaining there is no STANDARD & SECURE way to establish secrets (unlike say AES or Rabbit). That's not quite the same thing. Nearly everything has been designed to fail from the very beginning. Or are you saying you still trust "the experts" after everything that's happened?

Curve 25519 does not meet the ECRYPT recommendations of a min keylength of 512bits for Ellyptic Curves https://www.keylength.com/en/3/ Curve 25519 at 128bit provides:Very short-term protection against small organizations Should not be used for confidentiality in new systems

->OpenSSL since version 1.1.0

Probably the very worst example of an implementation you could give. OpenSSL version 1.1.0... Really????

There's a bounty of $100M (at the very least) for cracking 256-bit (128-bit strong) elliptic curves. It's called Bitcoin :)

So if they're broken - we'll know that very, very fast.

not true - the public blockchain means that cracking the encryption is only a very small part of such problem. You also need to convince all the other peers that you cracked it first

Because Bitcoin IS cracking encryption - bitcoins are assigned by doing exactly that.

In Bitcoin, a private key is usually a 256-bit number (giving a key length of at least 512 bits)

On the other hand, I'm sure all the MTgox customers will be happy with your assertion that their $450 million of missing/stolen funds allegedly stolen straight out of the MtGox hot wallet over time, beginning in late 2011. are actually still safe. Not sure they'll agree however.

I found some mention of a blockchain here: https://github.com/milagro-docs/docs.milagro.io-english/blob...

and here: https://github.com/milagro-docs/docs.milagro.io-english/blob...

For my taste, that's tying way too many systems and thinking about the operation and how to get a chain of trust out of it boggles the mind.

edit: Since you show enthusiasm for the topic, I'd like to share the most reasonable approaches for key distribution I found so far: http://named-data.net/publications/schematizing_trust_ndn/ and http://named-data.net/publications/techreports/ndn-0034-2-na...

Nice. I've found openpgp to be fit for purpose, there's even a js version for apps now: https://openpgpjs.org/

But still run into US import/export control problems with decent encryption. IMHO we can never have a standard as long as the US is involved in creating the standard, with obviously something never standing a chance of becoming a standard without the US being involved.

There's an accompanying talk (and slides) that was given at apachecon earlier in the summer. I heard some of the talk (from the OP linked page.. not in person) . The essence of DTA seems to be that it creates key-pairs for both ends of the communication (client and server), multiple DTA's combine to create the private keys and the keys are being distributed to the client side through some out-of-band "protected" channel.

The use-case is not billions of browsers connecting to millions of webservers (as in PKI based TLS) but a small number of controllable client end points (a native app binaries on mobile or IoT devices) connecting to a handful of servers.

The mental image I came away with (not sure if it's 100% correct) is think of an distributed infrastructure to create SSH key-pairs (where PIN is equivalent to the passphrase for the private key).

Wonder if anybody from the Milagro team feels like responding to this thread. It's on HN front-page right now and would be a great chance for the creators to engage with the community.

:( sounds terrible.

I went from eurphoria, to cynicism, to total foil hat in less than an hour.

This sounds incredibly like having multiple points of failure (what happens if one of the DTAs is unavailable?) and no public key cryptography (DTAs creating the secret key).

I'll freely admit to neither remotely being a security expert nor being completely confident I got the details right from listening to the talk. It really would help if someone from the actual team engaged the community here (or some other appropriate forum)

What is DTA? And why is it so bad for use in some code that seems to be for testing?

Wild Guess: Distributed Trust Authority

Its not the code, its the description of how the code should work in the comments.

->Their version of a CA tells both the client and the server the secret to use....

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