The Bitcoin Forum

Twitter verification: https://twitter.com/kristovatlas/status ... 2653171712

A few things about myself for anyone unfamiliar:

I’m a security engineer at Blockchain.info by day and privacy researcher by night.

I won’t be chatting about my work at Blockchain.info due to company policies, so if you have any BCI-specific questions please check out the AMA with Nic Cary on December 19th.

Some Bitcoin/cryptocurrency stuff I’ve done:

• Co-founded the Open Bitcoin Privacy Project: http://openbitcoinprivacyproject.org
• Wrote BIP 69
• Wrote a book about Bitcoin privacy: http://anonymousbitcoinbook.com
• Published research about BCI’s SharedCoin tool: http://coinjoinsudoku.com
• Performed a privacy and code audit of Dash in 2014 (formerly known as “Darkcoin”)
• Appeared on the Glenn Beck show with Jeffrey Tucker and Elizabeth Ploshay to talk about Bitcoin
• Co-organized the Bitcoin Philadelphia meetup group for about a year
• Gave a speech about the Silk Road and cryptographic free markets in Washington DC:
• Participated in shows on the World Crypto Network YouTube channel including The Bitcoin Group and Dark News.

Some of my interests include:

• Bitcoin economic theory
• Application security, malware forensics, and various other infosec topics
• Digital cash
• Financial and online privacy
• Cyberpunk art
• Cypherpunk action
• Cryptoanarchy
• Anarcho-capitalism
• Philosophy

Ok, I will leave two questions in wait since it seems I am the first to ask anything.

1.- Will there be a new OBPP privacy report anytime soon?

2.- Is there any new developments towards increasing privacy in Bitcoin Usage you are optimistic about?

Kristov,

I've been a follower of yours on Twitter for a while. I really appreciate the work you're doing to improve privacy in the Bitcoin space.

I like hardware wallets, but it seems that users must take an extra step to achieve privacy with hardware wallets. Paper wallets can be good for privacy, but are less convenient and take a bit of effort to securely create.

What would you say is the best security/privacy combo? I wish hardware wallers were compatible with Bitcoin Core.

I'm also interested on your thoughts on the block size. I've seen you mention it a few times on Twitter, but don't remember seeing any straight forward thoughts.

Thanks again for your work, and I'm looking forward to the next version of OBPP.

What's your take on Blockstream/Core/rBitcoin censorship?

Have you been part of the blockchain.info team when the RNG issue hit?

What wallet(s) do you use?

Which is the most important security procedure that noobs might don't know/ignore?

1.- Will there be a new OBPP privacy report anytime soon?

Yes, very soon. The next report will contain around 20 different wallet clients and include a significantly improved threat model, scoring system, and testing methodology. We've been working hard on it since the last report.

2.- Is there any new developments towards increasing privacy in Bitcoin Usage you are optimistic about?

Most of the developments in that space lately have been bad news, but there are a few good ones. Academics are getting more involved with Bitcoin privacy research and have contributed new p2p protocols such as CoinShuffle and CoinParty. We're also finally figuring out that these protocols require economic consideration, and so JoinMarket is a major advancement. I think a decentralized protocol that deals with the issue of input merging will catch on one day soon and make a big dent. This is an ongoing area of research for me.

In the long term, sidechains with new cryptographic primitives may allow things like Confidential Transactions or Zerocash. Lightning Network may prove to be a boon to privacy down the road, but I don't think we have a clear picture yet of what exactly LN will look like or when that may happen. These are all long-term strategies that may or may not come to pass, so we shouldn't hang our hat on them.

I've been a follower of yours on Twitter for a while. I really appreciate the work you're doing to improve privacy in the Bitcoin space.

Thanks a lot!

I like hardware wallets, but it seems that users must take an extra step to achieve privacy with hardware wallets. Paper wallets can be good for privacy, but are less convenient and take a bit of effort to securely create.

What would you say is the best security/privacy combo? I wish hardware wallers were compatible with Bitcoin Core.

I think Trezor has a pretty good user experience, particularly for intermediate users. It's cool that you can use it on web (mytrezor.com wallet) and Android (Mycelium).

A hardware wallet that you could use with a full node would, indeed, be nice. Even better would be the option to hook your mobile thin client up with your hardware wallet which does all balance lookups and transaction broadcasts through a full node that you setup yourself at home or perhaps a cloud-based virtual machine. Maybe a hardware wallet company can team up with BitSeed to make that happen.

I'm also interested on your thoughts on the block size. I've seen you mention it a few times on Twitter, but don't remember seeing any straight forward thoughts.

I would like to see greater consideration of economic solutions to the block size issue. I concur with those who identify block size limits as a production quota, which is inherently a blunt tool that will cause problems.

I'm not exactly sure what the solution is, but one approach I would like to see researched is to eliminate the block size limit altogether and to create a micropayment networks that offset the costs of running full nodes. Perhaps this approach could quell our fears about ever-decreasing full node counts and avoid a Bitcoin bread line.

Some people who have written great stuff in this area include Peter R and Justus Ranvier

Hi Kristov
Do you feel, as the Rat does, that the recent upsurge in interest in creating a "Blockchain without bitcoin" that is coming from the Banks and Financial Incumbents has huge opportunities for bitcoiners.

Put simply, all they will really create is an Intranet of self selecting permissioned gate-keepers , or let's be honest, a Cartel.

So, the motivation is for all of us that believe the future is decentralised, open-sourced and free of rent-seeking intermediaries to start creating the narrative that challenges the restrictive financial model they will start to push forward in 2016.

The Rat is quite positive that we can do this, we have enough enthusiasm and articulation to continue to put out there in public the Fraud, Corruption and Mistrust perpetuated by Bankers and Politicians. Each of us have skills and talents we can use, and together build this into a convincing argument.

Any thoughts on this ?

Can you tell us a bit about what initially motivated you to get involved with bitcoin, and if those same reasons are still driving you today?

What is your greatest fear regarding Bitcoin?

Thanks for all your great work!

Speaking in the now, what are the best ways to keep your bitcoin transactions private currently? Do you use SharedCoin or some sort of CoinJoin implementation, or another mixer? What wallets do you suggest that best promote privacy currently? I know there are some things on the horizon but I'm speaking in terms of right now for users to keep their tx's private. Any other tips to offer?

Thanks!

Hi Kristov,

how do you see the future of hashing algorithms and cryptography in general?
We still have A LOT OF government influence when it comes to how hashing algorithms are chosen, analyzed and deemed "acceptable" for worldwide use.

How could we reduce the amount of influence that government agencies have about this?

What would need to change to make this "market" (or shall we say "think thank") more decentralized?
So that we don't require any "stamp of approval" by NIST or NSA, etc...

Thanks

Do you feel, as the Rat does, that the recent upsurge in interest in creating a "Blockchain without bitcoin" that is coming from the Banks and Financial Incumbents has huge opportunities for bitcoiners.

Put simply, all they will really create is an Intranet of self selecting permissioned gate-keepers , or let's be honest, a Cartel.

So, the motivation is for all of us that believe the future is decentralised, open-sourced and free of rent-seeking intermediaries to start creating the narrative that challenges the restrictive financial model they will start to push forward in 2016.

The Rat is quite positive that we can do this, we have enough enthusiasm and articulation to continue to put out there in public the Fraud, Corruption and Mistrust perpetuated by Bankers and Politicians. Each of us have skills and talents we can use, and together build this into a convincing argument.

Any thoughts on this ?

Probably not. I think the average person is going to have a hard time appreciating the theoretical differences that distinguish Bitcoin from permissioned ledger stuff. For the most part, we will not not be able to control the media narrative; we're at a disadvantage there.

I think the fundamental differences will be expressed over time based on the quality of the products and services that are offered in these two realms. People will use what is of the greatest utility to them, and in the long-run, censorship resistant money is going to be more useful.

"Permissioned ledgers" are a five dollar term for a fifty cent approach to cryptographic database integrity. If this is the big innovation that the legacy financial system has finally discovered in 2015, it only shows how pathetically stunted innovation is in their industry right now.

Can you tell us a bit about what initially motivated you to get involved with bitcoin, and if those same reasons are still driving you today?

I've been really interested in the philosophy of liberty and infosec. Bitcoin is an intersection between those two, so it's a great topic to study and work on for me. Furthermore, I think it may be a viable tool for decreasing human violence by defunding the most violent elements of society. This is just as viable today as it was was the day I became interested.

What is your greatest fear regarding Bitcoin?

I'll list two:

1. The individual or group known as Satoshi had a rare comprehension of both computer science and economics. I fear that the future maintainers will become too focused on computer science and undermine the economic qualities of Bitcoin. There are probably several possible recovery modes for this scenario, though.

2. Lack of progress with blockchain privacy. We've been making a mess of the blockchain for years now and little effort has been put into fixing this. The wave of consequences for blockchain analytics is coming, and I'm not confident we're prepared for it.

Thanks for all your great work!

Thanks for the AMA invitation! I really enjoyed reading Gavin's AMA yesterday and look forward to more great discussions.

Kristov,

I'm a huge fan of your work. Your consistent and principled defense of privacy are an inspiration to many.

What do you think of "Confidential Transactions", the elements-alpha sidechain feature for privacy?

Andreas

Speaking in the now, what are the best ways to keep your bitcoin transactions private currently? Do you use SharedCoin or some sort of CoinJoin implementation, or another mixer?

As part of a "privacy in depth" strategy, I advocate using a chain of mixers, including SharedCoin. Bitcoin Fog is an interesting service, though in the long run I don't think centralized mixing services are a strong privacy defense.

What wallets do you suggest that best promote privacy currently?

I'll set aside the wallets made by the company that I work for, since I have obvious biases there. I don't think any wallet client is doing a great job with privacy right now, but some of the wallets I prefer are:

Mobile: Airbitz, Mycelium, and Breadwallet.
Desktop: Electrum for its easy use in Tails Linux, Armory for beefier machines.

I'm keeping a close eye on ArcBit and Samourai Wallet as potential up-and-comers in the mobile space.

Any other tips to offer?

Maintain multiple internet identities for different activities, and keep your funds for different identities segregated.

how do you see the future of hashing algorithms and cryptography in general?
We still have A LOT OF government influence when it comes to how hashing algorithms are chosen, analyzed and deemed "acceptable" for worldwide use.

How could we reduce the amount of influence that government agencies have about this?

What would need to change to make this "market" (or shall we say "think thank") more decentralized?
So that we don't require any "stamp of approval" by NIST or NSA, etc...

Putting on my amateur cryptographer hat for a moment...

Spies meddling in crypto standards have been a huge problem. I have no faith left in NIST after the Dual_EC_DRBG debacle. I'm only interested in standards bodies that can figure out how to mitigate tampering by spies. I'm not sure that we need to make the market more "decentralized," just be more selective about who we invite to the table.

Let's name names and start banishing individuals involved in backdooring from standards bodies, cryptographic conferences and mailing lists, etc. As long as we continue to respect the work of individuals who are paid to surreptitiously undermine security, we'll continue to get the same poisoned results.

Any interest in submitting some of your published work (if it can be revised a bit) to the new journal Ledger?

I'm a huge fan of your work. Your consistent and principled defense of privacy are an inspiration to many.

High praise, thanks.

What do you think of "Confidential Transactions", the elements-alpha sidechain feature for privacy?

CT is a great technology. Allowing it to influence the average Bitcoin user's transactions is going to take a long time, I think, because of the contentiousness of the hard fork changes we will likely need to the protocol. However, I tip my hat to Blockstream for getting it into production already with Liquid. Blockchain privacy for exchanges tends to land far below best practices right now, so this is a great product for them. Some privacy tech will be contextually appropriate rather than a tool that we try to roll out to the whole network.

To improve their users' privacy, I would like to see exchanges also implement BIP47 payment codes.

Any interest in submitting some of your published work (if it can be revised a bit) to the new journal Ledger?

I have a couple lines of research that might be suitable for inclusion in such a journal, if only I can find the time to hone them to a proper standard of quality and formatting.

Hi, Kristov

Thanks for doing this AMA.

How much backdooring are being done, and what is being done to warn general consumers about these practices?

Continue the good work.

Hi Kristov,

how are you storing your bitcoin?


LCG

how are you storing your bitcoin?

I have a few stashes. Some is difficult-to-access cold storage, some on hardware wallets, and some spending monies on hot wallets. How about you?

How much backdooring are being done, and what is being done to warn general consumers about these practices?

Hard to say. Some pretty important software projects have been confirmed or heavily suspected of backdoors, including NIST crypto algorithms, OpenSSL, various Linux distributions, Mirosoft's disk encryption solution...

Mostly, general consumers are unaware of these practices. :/

how are you storing your bitcoin?

I have a few stashes. Some is difficult-to-access cold storage, some on hardware wallets, and some spending monies on hot wallets. How about you?

thx for your answer.

i do it in a similar way and always recommend to use more than one method of storing.

for example:

1/3 : deep cold storage
2/3: hardware wallet
3/3: Paper Wallets



good to have you here. maybe you can visit the "Development & Technical Discussion" area from time to time

Hey Kristov, thanks for doing this AMA!

What are your thoughts on these "private blockchains"? From my understanding of Bitcoin, the only reason it uses a blockchain is because of it's decentralized nature. Am I missing something? What benefits would a "private blockchain" provide that a traditional database wouldn't?

Other than bitcoin, what technology do you think poses the greatest risk to the current nationstate power paradigm?

No question, just wanted to say thanks for all you are doing!! Great to watch you on youtube as well.

Hi Kristov

What do you think about Monero or Cryptonote in general?

getmonero.org
https://cryptonote.org/whitepaper.pdf

What's your take on Blockstream/Core/rBitcoin censorship?

Censorship sucks. Glad to see a variety of communication tools popping up -- may the best win!

Have you been part of the blockchain.info team when the RNG issue hit?

I started working at BCI toward the very end of last December.

Which is the most important security procedure that noobs might don't know/ignore?

When using centralized services that hold your private keys, get your funds out as fast as possible, regardless of the company's reputation. No one has figured out how to hold onto customer funds safely yet. In other words, don't get Zhou Tong'd or Gox'd!

Other than bitcoin, what technology do you think poses the greatest risk to the current nationstate power paradigm?

1. Censorship-resistant marketplaces.
2. Smart-contracts that award damages regardless of legal outcomes.
3. Possibly censorship-resistant prediction markets? Need to ponder and discuss this one some more.

What technologies are you looking at in this area?

Hi Kristov

What do you think about Monero or Cryptonote in general?

getmonero.org
https://cryptonote.org/whitepaper.pdf

Monero is awesome. Nicholas van Saberhagen is a pretty epic person (or group, or alien AI).

With altcoins in general I mentally separate them into two categories: Functionality and value. Monero has really cool functionality. I would find it the most useful if its value was two-way pegged to bitcoin because of the network effect of currency. Maybe one day on sidechains.

For a while people have been talking about using privacy-centric altcoins as Bitcoin mixers, but I haven't seen any implementations yet. Maybe ShapeShift.io will make it happen?

It would be nice if a fraction of the money and time invested into improving privacy in new altcoins were invested into doing that for Bitcoin.

Hi Kristov,

great to have you here!



1. What is your opinion about CISA / CISPA?

2. What about the UK attempt to ban end-to-end encryption? If Cameron's proposal passes, what is the following scenario for UK?

3. If you wanted to give 3-5 simple advise on protecting privacy and online security to my mom, what would you tell her?