Topic: The next step in going against "conventional wisdom" - Create your own Crypto! - page 2. (Read 1731 times)

That alone says a lot about your understanding of current affairs.

What the NSA is, is an enemy to privacy, and not just them, most intelligence agencies are. They've had more influence on crypto than bitcoin has had on the world. put that comparison to thought if you want to understand "the paranoid behavior"

"If you don't like what you see here - get the funk out."

(Extreme II)

Interesting - not a single question about any algo I have (supposedly) written but instead a lot of lecturing (funny how people are so happy to tell you not to write any code rather than review any code you have written).

For all you armchair critics know I have simply put a standard OpenSSL call in a function wrapper!



As for the NSA it is not paranoia but actual known issues made public by Wikileaks that I am referring to.

I don't quite understand the paranoid behavior so many of you here display at the NSA. The NSA is not an omnipotetnt all knowing being, it's simply an organization for America's security.

The NSA more likely than not, has had hardly if any any influence on crypto. If they did, then Bitcoin would not have reached where it has today. All the scams and thefts that have rocketed cryptocoins the past year(s) were created mostly by people we know the identities of. The guy who scammed people with his ponzi for millions of Bitcoin, was arrested. Charlie Shrem, was arrested. The guy who scammed the Mintpal users, we know how he looks like, etc etc.

If you actually look at the facts and details, you'd find that most of the big scams going on or that have happened in crypto are not secretive, the identities of the scammers are known, it's just catching them/putting them in jail that awaits.

So please, stop with your damn paranoia. It's annoying.

So, how many of these "NSA" algorithms have you personally broken? That's not an unfair question: remember Schneier's Law: "Anyone can create an algorithm that he himself can't break." And your inability to break your own algorithm means nothing if you are unable to break any other algorithms. Nobody will take your cryptography seriously unless you have a lot of experience in breaking other people's algorithms, and rightly so.

Bruce Schneier provides a self-study course in cryptanalysis. Start here and don't even dream of rolling your own crypto until you've broken most of the algorithms in that paper. And no cheating.

You have to be really clear whether you are against "reimplementing code" from the libraries or "inventing hokey-pokey algorithms". In particular SSLeay/OpenSSL is a swiss-army-harvester-combine-cum-crutch that is a culprit of many bugs and inconsistencies in many, many codebases. It is not uncommon for a undergrad-student-level exercise projects to beat the efficiency of the supposedly well optimized code from the well-known cryptographic libraries, both open source and for-pay source.

In particular rewriting conventional crypto implementations to properly take advantage of the SIMD instructions that are now available in nearly every processor gives great payoffs in terms of power efficiency and resistance to various attacks.

One thing is the PhD-level knowledge of relevant mathematics/algebra and the other thing is simple patience and careful craftsmanship required to write clear and neat code. There's lots of the source code available out there that for the expedience of portability and meeting some very narrow benchmarking goals had completely forsaken readability and maintainability.

Because it takes a PHd level knowledge and about 10 years directly working at breaking crypto implementations to roll your own crypto libraries. That's basically what people mean by "don't roll your own crypto" it means don't invent libraries, use the already well established, and tested ones. For example libsodium is good to use if you want to create an encrypted chat/video program like Tox does.

Colin Percival (FreeBSD developer, owner of Tarsnap) gives a good talk about what you need to know about implementing crypto in w/e software you're doing:
https://www.youtube.com/watch?v=jzY3m5Kv7Y8

For example, cpercival does not use XTS or other block modes for Tarsnap cloud storage and for good reason, because there are all sorts of attacks that can be done to XTS once it is freed from the physical confines of disk geometry.

+1000

and the "bitcoin is the be all and is all" mentality being forced onto people is not helping.

I did not know that insult. Cypherfunk is probably someone partway between cypherpunk and cypherflunk. 

It's more a case that naively glomming stuff together can tend to create edge cases and create insecure patterns, one can unknowingly create backdoors and shortcuts. Re-implementing well known algorithms can also have many pitfalls for the unwary.

One can only gain much confidence in one's work if the cypher is under constant attack for a long period and remains secure. Getting that level of real world testing "just for the hell of it" is unlikely.

Basically, you can give yourself a false sense of security behind something with critical weaknesses, just because nobody finds what you're protecting with it interesting or lucrative... then after 5 years of patting yourself on the back you use it for something that MATTERS and bam, fucked over in a weekend.

Personally I think it would be really strange that true cypherfunks would be so adverse to helping people who are trying to work out how to play with encryption.

If they really are so arrogant then it is clear why they have lost to the NSA and other such organisations.

I think you have mistaken me for someone naively creating a "new crypto algo".

I am not doing that at all (SHA256 is actually used by Linux systems for /var/random when physical random data is not available - so unless you are going to suggest that the Linux kernel devs are idiots then perhaps you can stop comparing me to some newbies).

It is interesting how the "arrogance" of the above posts (you referenced) came about - if I were the NSA and I wanted to stop anyone questioning about crypto that is exactly the approach I think I'd use also.

Perhaps the cypherfunks were too naive themselves - they got infiltrated by NSA and didn't even realise it - so next thing they are recommending everyone in the world to not think and just do what they are told with the banner "trust us".

If I were a cypherfunk then I think I would be *ashamed* to be so quiet.

Good points - I am not inventing a new type of cypher.

The idea of a OTP is at least hundreds of years old.

The only idea I would ask anyone to accept is that "secure hashes are secure" (as many other crypto algos work upon that assumption I don't think I have violated any sacrosanct idea).

If SHA256 is not secure then Bitcoin should have already been destroyed (and that is the OTP method that I use).

Points from the Cypherpunks FAQ ...


edit: also ...

A good point - as stated - this topic is not intended for those without the necessary skills (the question I am raising is exactly how much skill is required).

Many have tried to point out that I should be incompetent to create a brainwallet - yet my brainwallet stands (and anyone with any brains knows that there are bots working 24x7 to crack brainwallets).

So I accept your criticism but also just point out that I am somehow able to beat the odds (do you think that is just luck - especially after I've published my address for months?).

So let's start with a very simple but important thing - the "one time pad".

It is actually the best method of encryption in existence as it only relies upon the two sides having a shared secret at one point in time.

Before asymmetrical crypto was implemented the issue was "how to exchange keys" but of course that is now much easier using DSA technology. There is still however some problems with trusting the keys that are used that could only be solved by offline (or direct) communication.

But assuming we are happy that we have solved the issue of exchanging a key (whether via GPG or an in person meeting) then we can start to build a secure method to exchange messages without needing to use any 3rd party software.

The biggest reason why not is because you yourself are blind to the ways in which you are incompetent.

You don't know what you don't know.

I created a topic about "brainwallets" that some of you might have followed (https://bitcointalksearch.org/topic/a-challenge-to-the-idea-that-no-one-can-create-a-good-brainwallet-885616) where I challenged the idea that "no-one can create a secure brainwallet".

I pointed out my own brainwallet address with 1 BTC (https://blockchain.info/address/1Au4v6dZacFVsWXeKUMJd99AtyBZeqti2L) and it still has that 1 BTC there (so those wanting to show that you can't create a good brainwallet are not doing a good job in that they seemingly are unable to sweep that 1 BTC and it has been there for a long time - and as I took out 9 BTC previously the public key is available also).

My next challenge to conventional thinking is with crypto itself. We are constantly told *don't roll your own crypto* and for sure just like *don't create a brainwallet* it is not something that *anyone can do* but I think that those who are smart enough to create a brainwallet should also be thinking about exercising their skills at creating crypto (if they are keen to work out how to do so).

Why?

Because maybe you shouldn't trust anyone else to create it for you.

Everyone here should be well aware that any publicly created crypto could likely have been influenced by the NSA or other groups (as has already been exposed by Wikileaks and others).

So I prefer that we discuss ways of creating new crypto rather than saying "we can't discuss that as we are not qualified". As that is the easiest argument to force everyone to use unsafe software (i.e. don't think for yourself just use what *we say you should use*).