Interview: Alan Reiner from Bitcoin Armory discussing ...
Interview: Alan Reiner from Bitcoin Armory discussing ...
An Interview with Armory Technologies CEO Alan Reiner ...
Achtung vor diesen falschen, "inflationsgeschützten ...
Alan Reiner - Bitcoin Security Experte 2020 - Dobrebit Coin
Bitcoin Lead Developer Gavin Andresen on Origins, Expectations, Projects & Pitfalls. Alan Reiner of Armory Wallet, Bitcoin powered Tor & Wi-Fi Nodes, And Feathercoin Lead Developer. Catch it all here for Let's Talk Bitcoin! Episode 015
WARNING: A fake electrum website with malware is advertising on duckduckgo and yahoo.
If you perform a search for electrum on duckduckgo or yahoo, an ad claiming to be electrum.org will be at the top. In reality the ad links to: electrum-bitcoin org The domain was created December 21. This site is nearly identical to electrum.org except the download links give different files. All three of the files that can be download are much smaller than the real electrum and are most likely malware. The three files are: electrum.exe - 91136 bytes electrum.out - 60316 bytes electrum.zip - 32478 bytes EDIT: Some Advice: When installing software, especially something as import as wallet software, it is a good idea to verify the integrity of the download with a signature using a key that was obtained from one or more seperate sources. I made a list of the keys used to sign popular bitcoin wallets below to act as another source to verify the integrity of those keys. Bitcoin-Qt: Signer: Gavin Andresen [email protected] Fingerprint: 2664 6D99 CBAE C9B8 1982 EF60 29D9 EE6B 1FC7 30C1 Key ID: 1FC730C1 Key Link: bitcoin.org/gavinandresen.asc Electrum: Signer: ThomasV [email protected] Fingerprint: 6694 D8DE 7BE8 EE56 31BE D950 2BD5 824B 7F94 70E6 Key ID: 7F9470E6 Keyserver: pool.sks-keyservers.net Multibit: Signer: Jim Burton (multibit.org developer) [email protected] Fingerprint: 299C 423C 672F 47F4 756A 6BA4 C197 2AED 79F7 C572 Key ID: 79F7C572 Keyserver: pgp.mit.edu Armory: Signer: Alan C. Reiner (Offline Signing Key) [email protected] Fingerprint: 821F 1229 36BD D565 366A C36A 4AB1 6AEA 9883 2223 Key ID: 98832223 Keyserver: pgp.mit.edu The signatures provided for some of the wallets are signatures of the hash values, so be sure to verify that the hash of the downloaded file matches the hash that was signed. EDIT: GPG Examples: Verifying Bitcoin-Qt: First download, import and check Gavin's key: Download his key at bitcoin.org/gavinandresen.asc In terminal or command line run:
gpg --import gavinandresen.asc gpg --fingerprint
Check that the fingerprint for Gavin's key matches 01CD F462 7A3B 88AA E4A5 71C8 7588 242F BE38 D3A8. Then download the wallet software and signature. Verify the signature:
gpg --verify SHA256SUMS.asc
You should see:
gpg: Good signature from "Gavin Andresen (CODE SIGNING KEY) "
The signature for Bitcoin-Qt signs the hash values. So we must compute the hash of the downloaded software. This example is using the linux version.
gpg --print-md SHA256 bitcoin-0.8.6-linux.tar.gz
Check that the output matches the associated hash value in SHA256SUMS.asc Verifying Electrum: First download, import and check ThomasV's key: This key can be found at a keyserver.
Rolling UTXO set hashes | Pieter Wuille | May 15 2017
Pieter Wuille on May 15 2017: Hello all, I would like to discuss a way of computing a UTXO set hash that is very efficient to update, but does not support any compact proofs of existence or non-existence. Much has been written on the topic of various data structures and derived hashes for the UTXO/TXO set before (including Alan Reiner's trust-free lite nodes , Peter Todd's TXO MMR commitments  , or Bram Cohen's TXO bitfield ). They all provide interesting extra functionality or tradeoffs, but require invasive changes to the P2P protocol or how wallets work, or force nodes to maintain their database in a normative fashion. Instead, here I focus on an efficient hash that supports nothing but comparing two UTXO sets. However, it is not incompatible with any of those other approaches, so we can gain some of the advantages of a UTXO hash without adopting something that may be incompatible with future protocol enhancements.
Computing a hash of the UTXO set is easy when it does not need efficient updates, and when we can assume a fixed serialization with a normative ordering for the data in it - just serialize the whole thing and hash it. As different software or releases may use different database models for the UTXO set, a solution that is order-independent would seem preferable. This brings us to the problem of computing a hash of unordered data. Several approaches that accomplish this through incremental hashing were suggested in , including XHASH, AdHash, and MuHash. XHASH consists of first hashing all the set elements independently, and XORing all those hashes together. This is insecure, as Gaussian elimination can easily find a subset of random hashes that XOR to a given value. AdHash/MuHash are similar, except addition/multiplication modulo a large prime are used instead of XOR. Wagner  showed that attacking XHASH or AdHash is an instance of a generalized birthday problem (called the k-sum problem in his paper, with unrestricted k), and gives a O(22*sqrt(n-1)) algorithm to attack it (for n-bit hashes). As a result, AdHash with 256-bit hashes only has 31 bits of security. Thankfully,  also shows that the k-sum problem cannot be efficiently solved in groups in which the discrete logarithm problem is hard, as an efficient k-sum solver can be used to compute discrete logarithms. As a result, MuHash modulo a sufficiently large safe prime is provably secure under the DL assumption. Common guidelines on security parameters  say that 3072-bit DL has about 128 bits of security. A final 256-bit hash can be applied to the 3072-bit result without loss of security to reduce the final size. An alternative to multiplication modulo a prime is using an elliptic curve group. Due to the ECDLP assumption, which the security of Bitcoin signatures already relies on, this also results in security against k-sum solving. This approach is used in the Elliptic Curve Multiset Hash (ECMH) in . For this to work, we must "hash onto a curve point" in a way that results in points without known discrete logarithm. The paper suggests using (controversial) binary elliptic curves to make that operation efficient. If we only consider secp256k1, one approach is just reading potential X coordinates from a PRNG until one is found that has a corresponding Y coordinate according to the curve equation. On average, 2 iterations are needed. A constant time algorithm to hash onto the curve exists as well , but it is only slightly faster and is much more complicated to implement. AdHash-like constructions with a sufficiently large intermediate hash can be made secure against Wagner's algorithm, as suggested in . 4160-bit hashes would be needed for 128 bits of security. When repetition is allowed,  gives a stronger attack against AdHash, suggesting that as much as 400000 bits are needed. While repetition is not directly an issue for our use case, it would be nice if verification software would not be required to check for duplicated entries.
Efficient addition and deletion
Interestingly, both ECMH and MuHash not only support adding set elements in any order but also deleting in any order. As a result, we can simply maintain a running sum for the UTXO set as a whole, and add/subtract when creating/spending an output in it. In the case of MuHash it is slightly more complicated, as computing an inverse is relatively expensive. This can be solved by representing the running value as a fraction, and multiplying created elements into the numerator and spent elements into the denominator. Only when the final hash is desired, a single modular inverse and multiplication is needed to combine the two. As the update operations are also associative, H(a)+H(b)+H(c)+H(d) can in fact be computed as (H(a)+H(b)) + (H(c)+H(d)). This implies that all of this is perfectly parallellizable: each thread can process an arbitrary subset of the update operations, allowing them to be efficiently combined later.
Comparison of approaches
Numbers below are based on preliminary benchmarks on a single thread of a i7-6820HQ CPU running at 3.4GHz. (1) (MuHash) Multiplying 3072-bit hashes mod 23072 - 1103717 (the largest 3072-bit safe prime).
* Needs a fast modular multiplication/inverse implementation. * Using SHA512 + ChaCha20 for generating the hashes takes 1.2us per element. * Modular multiplication using GMP takes 1.5us per element (2.5us
with a 60-line C+asm implementation).
* 768 bytes for maintaining a running sum (384 for numerator, 384
* Very common security assumption. Even if the DL assumption would
be broken (but no k-sum algorithm faster than Wagner's is found), this still maintains 110 bits of security. (2) (ECMH) Adding secp256k1 EC points
* Much more complicated than the previous approaches when
implementing from scratch, but almost no extra complexity when ECDSA secp256k1 signature validation is already implemented.
* Using SHA512 + libsecp256k1's point decompression for generating
the points takes 11us per element on average.
* Addition/subtracting of N points takes 5.25us + 0.25us*N. * 64 bytes for a running sum. * Identical security assumption as Bitcoin's signatures.
Using the numbers above, we find that:
Computing the hash from just the UTXO set takes (1) 2m15s (2) 9m20s
Processing all creations and spends in an average block takes (1)
24ms (2) 100ms
Processing precomputed per-transaction aggregates in an average
block takes (1) 3ms (2) 0.5ms Note that while (2) has higher CPU usage than (1) in general, it has lower latency when using precomputed per-transaction aggregates. Using such aggregates is also more feasible as they're only 64 bytes rather than 768. Because of simplicity, (1) has my preference. Overall, these numbers are sufficiently low (note that they can be parallellized) that it would be reasonable for full nodes and/or other software to always maintain one of them, and effectively have a rolling cryptographical checksum of the UTXO set at all times.
Replacement for Bitcoin Core's gettxoutsetinfo RPC's hash
computation. This currently requires minutes of I/O and CPU, as it serializes and hashes the entire UTXO set. A rolling set hash would make this instant, making the whole RPC much more usable for sanity checking.
Assisting in implementation of fast sync methods with known good
Database consistency checking: by remembering the UTXO set hash of
GPG instructions and public key list for verifying Bitcoin clients.
I have noticed their is a growing problem of fake bitcoin clients, and I expect the frequency and elaboratness of these fake clients to increase. Verifying the signatures for these clients will detect if you are receiving anything other than what the signer the of the software signed. The exception to this is if the attacker acquires the signer's private key, which should be a lot more difficult than tricking users to visit the wrong site or hacking servers. This can also be addressed by using multiple signatures per client. An important part of this process is acquiring the public keys for the sofware signers in a secure manner. To help with this I have included a signed list of fingerprints and where to acquire the public keys to act as another source to verify the keys used to sign bitcoin clients. I have also included instructions for verifying the fingerprint list and bitcoin clients. To deal with the issue that posts and comments on Reddit can be easily modified I suggest other users (especially well known ones) post a signature of the fingerprint list in a comment in this thread, or at least a hash of the fingerprint list (not as secure but still better than nothing). List of Fingerprints: +++ Bitcoin-Qt: Signer: Gavin Andresen (CODE SIGNING KEY) [email protected] Fingerprint: 2664 6D99 CBAE C9B8 1982 EF60 29D9 EE6B 1FC7 30C1 Key ID: 1FC730C1 Key Link: bitcoin.org/gavinandresen.asc Electrum: Signer: ThomasV [email protected] Fingerprint: 6694 D8DE 7BE8 EE56 31BE D950 2BD5 824B 7F94 70E6 Key ID: 7F9470E6 Keyserver: pool.sks-keyservers.net Signer: Animazing [email protected] Fingerprint: 9914 864D FC33 499C 6CA2 BEEA 2245 3004 6955 06FD Key ID: 695506FD Keyserver: pool.sks-keyservers.net Multibit: Signer: Jim Burton (multibit.org developer) [email protected] Fingerprint: 299C 423C 672F 47F4 756A 6BA4 C197 2AED 79F7 C572 Key ID: 79F7C572 Keyserver: pgp.mit.edu Armory: Signer: Alan C. Reiner (Offline Signing Key) [email protected] Fingerprint: 821F 1229 36BD D565 366A C36A 4AB1 6AEA 9883 2223 Key ID: 98832223 Keyserver: pgp.mit.edu +++ My Key:
Hashes for fingerprint list: SHA-256: 7A6B9841 355B1127 E5639A9D 7040D81C F395D382 884376C2 31829C63 6FCF1B80 SHA-512: 04A49A60 A1645479 ED0B3CE9 AE32E156 E9768CC2 0D4EF393 814162BE BFA6FAF5 6C520769 C654467F 6B61EBD4 4A5A5C93 9DF81B7D AA468A50 2DD7FFF3 F637A49C Verifying the fingerprint list: Save fingerprint list, from the first plus to the last plus, to a text file called fingerprints.txt Next save my key to a file called dcc4e.asc and my signature to a file called fingerprints.txt.asc In terminal or command line run:
Bitcoin Wallets generate and store the private keys that control a user's funds. These keys are simply random numbers, chosen by the wallet from a range of numbers so vast that it is essentially impossible for there to be a collision with another wallet doing the same thing. Deterministic wallets, also known as HD wallets help to simplify backing up and restoring wallets by using a random seed number to deterministically generate all of a wallet's private keys.
Private Key Backups
Whenever a Bitcoin user receives funds, they need a new private key. This means that the set of numbers that are important to store and back up is increasing indefinitely. In the original Bitcoin wallet, this required refreshing a back-up with a new one every time a user received funds. Over time, Bitcoin grew more valuable and this burden of security grew more tiresome and costly. To address the issue Satoshi Nakamoto in October of 2010 released Bitcoin version 0.3.14 which contained a key pool feature. This feature automatically pre-generated a set of keys, to remain in abeyance for the user's next receipt of funds. This made backing up a much less frequent necessity, only being necessary after key pool exhaustion. Over the following years, many other methods of improving key backups were tried. A popular concept of a paper wallet arose: printing a private key onto paper to store in a secure location. However this concept fell out of favor as being too complicated, vulnerable to printer information leaks, and encouraging address re-use.
Type 1 Deterministic Wallets
In August of 2011 Mike Caldwell sought to simplify and streamline the process of managing a collection of private keys. He created a Windows application called Bitcoin Address Utility that used a single random pass-phrase to deterministically create private keys from a single seed: essentially choosing one random number and then feeding it into a formula that would always produce more random numbers from the starting one. This created a much easier way to backup private keys: simply secure the original random seed and restoring becomes a simple exercise of running the seed through the algorithm again.
Type 2 Deterministic Wallets
Mike Caldwell's Type 1 deterministic wallet design was based on a simple scheme that had a significant limitation: to receive funds with a Type 1 wallet required also having access to the private keys that could spend them. In situations such as merchant scripts or exchange wallets, this represented a security issue. Before Mike Caldwell published his Type 1 wallet, in June of 2011 Greg Maxwell had already outlined a theoretical improvement to the Type 1 scheme, in which the public and private key generation might be separated to improve the security of stored funds. In Greg's outlined Type 2 scheme, a script could use what is called a master public key to generate new addresses, without ever being able to spend those funds. In February of 2012, Pieter Wuille came up with a formalization and standardized version of this concept, in BIP 32. A surge of wallet development activity followed the deterministic wallet concept. Since the master seed behind the wallet may be represented as a simple series of twelve words, it was widely considered to be the superior method for Bitcoin wallet private key generation. Alan Reiner was the first to implement a Type 2 seed in Armory Wallet, and helped give feedback to the BIP 32 formalization. Since then, every major wallet has moved to support the feature.
BIP 44 Deterministic Wallets
After BIP 32, development of Type 2 deterministic wallets progressed to a state where additional features and standardization was sought to be defined. In April of 2014 Marek Palatinus, also known as Slush, and Pavol Rusnak, Slush's employee at his company SatoshiLabs, sought to advance the state of deterministic wallets by adapting advancements in their own Type 2 hardware wallet Trezor into a standard they authored in BIP 44. Features promoted by the BIP 44 standard included a mechanism for internal pass-phrase protected accounts inside of a wallet seed, a standard for using the wallet seed across multiple chains, such as for Bitcoin Testnet, and an increased standardization of gap limits and change address separation.
Deterministic Wallet Caveats
Despite the huge improvement in the state of Bitcoin technology that HD wallets represent, there are some outstanding issues and drawbacks or gotchas that may present difficulties. Deterministic wallets generally present users with a dictionary derived random pass-phrase that actually represents a master seed number in a form that is easier for humans to deal with. But this ease-of-use has sometimes tempted developers into allowing users to set their own pass-phrase, a very bad idea. Users are extremely bad at choosing a properly random pass-phrase, and this behavior can lead to loss of funds. For this reason, all well-maintained wallets have ceased the practice of encouraging users to invent their own pass-phrases. Another issue that sometimes confronts users in unexpected ways is that the seeds created by deterministic wallets should not be shared between wallets from different software projects. The reason for this is that the standard for deterministic wallets is generally not actually adopted by all wallets, or there are still areas left unspecified. Due to these small differences, seeds may superficially appear to be share-able between wallets, but in actuality leave some coins difficult to access from the non-originating wallet. To switch between deterministic wallets, the best practice recommendation is to initiate fund transfers on the Blockchain. From a security and privacy perspective, under normal circumstances a deterministic wallet is just as good as a wallet in which random keys are individually generated. However use of the public master key can prove the exception to that rule. Although it is called a public master key, for privacy reasons it should not be shared publicly, as it can link all wallet addresses together. Another important reason it should not be shared is that if a single private key derived from the private seed is leaked and the public master key is also known, all the other private keys may be derived as well. This type of theft is quite uncommon, but for these reasons it is strongly recommended that the master public key still be treated as guarded information. One practice that must differ between using an individually generated wallet and a deterministic wallet is the practice of creating addresses that are never used. HD wallets have a key implementation detail in the way that they calculate wallet balances: they go through their deterministic algorithm sequentially to determine if each private key has been used, stopping when no further activity is detected. This is a critical optimization, an HD wallet cannot scan endlessly or know automatically all of its balance information without individual queries. To provide a safety margin, HD wallets use something called a gap limit, which represents the number of keys checked that have no activity before the balance query will cease its sequential checking. This gap limit can means that creating many addresses that are never used is a bad practice and can lead to users mistakenly believing their funds have been lost, if more unused addresses are created beyond the gap limit safety margin. A powerful feature of BIP 44 HD wallets is the internal pass phrase account system. This feature addresses a common security concern amongst people who worry about keeping their seed backups secure from theft: it adds an internal password to the stored seed. The feature also powers another use-case, a scenario in which the owner is confronted with the seed and forced to give access to it. As a precautionary measure, the owner may create a red-herring pass phrase and a real pass-phrase, pretending that the red-herring phrase contains the entirety of the funds when forced to open the wallet under duress. But with this power also comes risk deriving from any situation where users choose pass phrases to remember. Human generated pass phrases should generally be considered weak: a brute-force attack can most often bypass them. And memorized pass phrases can be easily forgotten, leading to an annoying situation where funds are temporarily inaccessible, or if a truly strong pass-phrase has been chosen, permanently lost.
Why Bitcoin is and isn't like the Internet | 21E14 | Jan 21 2015
21E14 on Jan 21 2015: This is a response to a wonderfully insightful recent post by Joichi Ito, the Director of the MIT Media Lab. In it, Dr. Ito, notably a former Board Member of ICANN, offered his thoughts on "Why Bitcoin is and isn't like the Internet" and asked a most pertinent question: "Whether there is an ICANN equivalent needed for Bitcoin." As suggested in recent posts to the mailing list, I believe there might be, but for a reason that may not seem obvious at first. Alan Reiner expressed the need this way: "I think one of the biggest issues facing Bitcoin right now is not the lack of a 'killer app.' It is lack of insurance options. Early adopters would like to believe that the majority of users will hold their own Bitcoin, but I believe that is not a realistic option when life-changing quantities of Bitcoin are involved. We should not trust Grandma to secure her own retirement savings via complicated computer maneuvers. More to the point, she should not trust herself or anyone else (sic!) to hold it unless there is a strong protection against loss events. Right now the solution is for Grandma to avoid keeping her money in Bitcoin. Bitcoin needs a strong backbone of insured storage options so that Grandma can confidently participate in this new technology." This is certainly an observation to take heed of coming from the founder of Armory Technologies. The protection against loss events ought to be understood in the broadest sense. What is needed is a disaster recovery mechanism. Andreas Antonopoulos remarks expressed this candidly last year: "Bitcoin doesn't have a middle of the road mediocre growth model. It basically either dies, because of a fundamental flaw in the Bitcoin system. Not an external factor, an internal factor: We blow it up by accident. And that could happen... Bitcoin will play out in the next three years. In the next three years we're going to see Bitcoin arrive on the global stage and make a substantial impact, both in financial terms and in political terms. It will happen. Or it will die. Either way. I'm not sure. In which case we'll reboot another currency." A body, not entirely unlike ICANN, can manage the nexus to the physical world, and help address Bitcoin's catastrophic failure modes. Bitcoin's coin ownership protocol would thus join the ranks of its payment protocol, coin issuance protocol, consensus mechanism and inflation control that pose no lethal threat to the ecosystem. In addition to their coin-agnostic nature, I suspect the high valuation of large Bitcoin hubs relative to Bitcoin's market cap at this stage in its lifecycle is partly reflective of the sneaking suspicion that a custodial bitcoin (a bitcoin attached to an identity) may be worth more than a non-custodial one. With this in mind, I'll pitch in for the ticket should Dr. Ito decide to join the next month's DevCore Boston conference aimed at supporting the future development of Bitcoin. It's an hour's walk from MIT after all. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20150121/45fa2d7d/attachment.html> original: http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-January/007158.html
Portland - Após aumentarem em 90 vezes seu valor no ano passado, os Bitcoins se tornaram um alvo atraente para hackers e ladrões, gerando uma oferta cada vez maior de startups criadas para proteger o dinheiro virtual dos investidores contra perdas. Desde a criação da moeda, ocorreram mais de 35 grandes fraudes e furtos de Bitcoins no mundo, incluindo o roubo de 38.527 Bitcoins da casa de câmbio on-line Bitcoinica LLC, em maio de 2012, segundo o site BitcoinTalk.org. Cerca de uma dúzia de startups, de uma empresa que fabrica moedas chamada Titan Mint Inc. a um mercado chamado BitShares que permite que as pessoas troquem Bitcoins entre si, busca amenizar as preocupações a respeito da vulnerabilidade do Bitcoin. Estas empresas oferecem de tudo, desde moedas de metal estampadas com códigos de segurança até contas on-line criptografadas. “O risco existe e é suficiente para afastar alguns usuários”, disse Nicholas Colas, estrategista-chefe de mercado do grupo ConvergEx em Nova York. Ele estima que mais Bitcoins são perdidos para bandidos e hackers hoje do que dólares para ladrões de banco. Uma vez que os Bitcoins são armazenados como arquivos de software em “carteiras” ou pastas em sites, computadores pessoais ou smartphones, isso deixa seus donos suscetíveis a perdas para ladrões, falhas ou hackers. E devido ao fato de que o dinheiro digital foi desenvolvido para ser difícil de rastrear, qualquer saque é semelhante a um saque em dinheiro e é mais difícil de monitorar que o dinheiro real guardado em contas bancárias. O valor exorbitante dos Bitcoins, que aumentou de US$ 12 no início de 2013 para mais de US$ 1.000 em novembro, transformou-os em um alvo mais tentador, de modo que os esforços extras de proteção compensam. Dinheiro real De um total de um milhão de pessoas com carteiras de Bitcoin, alguns milhares perderam seus fundos, segundo Andreas Antonopoulos, um analista de segurança de Bitcoins. O alcance dos roubos é difícil de medir, porque os Bitcoins são feitos para serem uma moeda autônoma difícil de rastrear. Criado em 2008 por um programador ou grupo de programadores desconhecido, o Bitcoin tem seu fornecimento regulado pelo software básico da moeda e só pode ser feito através da solução de enigmas complexos incorporados ao código do Bitcoin. O dinheiro digital está sendo usado para comprar de tudo, desde chocolates até câmeras digitais na internet. Michail Wilson, administrador de sistemas de 42 anos de idade em Seattle, transformou suas reservas em moedas físicas da Titan Mint. Cada moeda -- que pode ser disponibilizada em ouro ou prata -- contém um código de resgate para desbloquear os Bitcoins. “Eu gosto da ideia de poder ter algo nas mãos”, disse Wilson, que contou que comprou 230 moedas da Titan e depois vendeu metade delas para outra pessoa. “Eu não tenho que me preocupar se serei hackeado. Eu posso simplesmente jogá-las em um cofre e não me preocupar mais se minha carteira será hackeada”. Alguns desenvolvedores de novas tecnologias de segurança do Bitcoin têm formação em criptografia e segurança militar. Alan Reiner -- CEO da Armory Technologies Inc., a produtora da Bitcoin Armory, carteira segura de Bitcoin que foi baixada 65.000 vezes nos últimos seis meses -- trabalhava com defesa antimísseis no Laboratório de Física Aplicada da Universidade Johns Hopkins. Oportunidades de segurança Ian Purton, desenvolvedor do StrongCoin.com, aprendeu sobre o Bitcoin enquanto desenvolvia softwares para bancos de investimentos. Dan Larimer, que está construindo uma casa de câmbio mais segura para a moeda, trabalhou com veículos robóticos. “Nós temos problemas de segurança, mas também temos oportunidades de segurança”, disse Antonopoulos, o analista de segurança, em uma entrevista. “Nós podemos inovar em relação ao dinheiro”. No caso das moedas da Titan, cada uma delas é registrada com um endereço de e-mail e uma senha, que são necessárias para resgatar o valor em Bitcoins armazenado com elas. Para usar as moedas, os usuários descascam um holograma de segurança para desvendar um código único de resgate. Tim Fillmore, presidente da Titan, disse que a empresa vendeu mais de 1.000 moedas desde que elas foram colocadas à venda, em setembro. “Elas são realmente pensadas para atrair os colecionadores de moedas e compradores tradicionais de ouro”, disse Fillmore. EXAME
Alan Reiner is founder and CEO of Fulton, Maryland-based Armory Technologies, Inc. and core developer of Armory Bitcoin Wallet, an open-source wallet application focused on security for enterprise business and advanced users. He has degrees in applied mathematics and engineering mechanics, and additional background in statistics, data mining and cryptography. Einige Bitcoin-Enthusiasten bezeichnen Kryptowährung als "digitales Gold." Damit liegen sie jedoch falsch. Während Bitcoin sicherlich an Nutzen und Wert besitzt, ist es nur ein digitales Asset o Search the world's information, including webpages, images, videos and more. Google has many special features to help you find exactly what you're looking for. limit my search to r/Bitcoin. use the following search parameters to narrow your results: subreddit:subreddit find submissions in "subreddit" author:username find submissions by "username" site:example.com find submissions from "example.com" url:text search for "text" in url selftext:text search for "text" in self post contents self:yes (or self:no) include (or exclude) self posts nsfw:yes (or ... Alan Reiner, Armory Technologies, bitcoin, Bitcoin 101, blockchain, Cold Storage, Conference, Interviews, investment, Jesse Powell, kraken, Money 20/20, Nicolas Cary, security, trace mayer, Video, wallet; I had the opportunity to sit down at Premier Studios with Trace Mayer as he got ready to attend this year’s Money 20/20 conference. Join us as Trace Mayer discusses the CEO panel of Bitcoin ...
OlgaShow interview of Alan Reiner, Armory BitCoin Client. Olga Media. Loading... Unsubscribe from Olga Media? ... Bitcoin - Trace Mayer at Inside Bitcoins 2013 Las Vegas - Duration: 21:06. THE ... Bitcoin Armory - Simulfunding a Lockbox "The US is bankrupt...and it's only going to get worse from here!" - Jeff Berwick Interview - Duration: 13:10. Cambridge House International Inc. Recommended for you Alan Reiner from Bitcoin Armory discussing mulit-sig Lock boxes - Duration: 3:09. Contrarian Dude 1,104 views. 3:09. How To Connect Two Routers On One Home Network Using A Lan Cable Stock Router ... This ident was produced as a test for Alan Reiner at the Bitcoin Armory www.bitcoinarmory.com It is presented here for demonstration purposes only.