9

TCP and other stream based protocols do not have a 1-to-1 correlation of application level messages and IP packets. If you call send() 3 times, it might result in sending a single IP packet over the wire (eg, due to Nagle's algorithm which is enabled by default), it might get sent individually as 3 packets, as you would expect from a packet oriented protocol ...


5

I've read simplistic descriptions of mining as simply incrementing the nonce until a solution is found, but I've also read much more detailed explanations which would imply much more is involved. Even if only the nonce is changed in the input, the pool would still need to assign each miner a unique nonce to try after each submission, no? Miners do change ...


5

We don't have federated servers right now but we do utilize open source, publicly accessible libbitcoin nodes which both Airbitz and 3rd parties host. This is a fully compatible replacement to bitcoind nodes but provides much faster blockchain queries, similar to Electrum servers. If you'd like to run one, we'll include it in the list of servers that our ...


5

Electrum servers don't save any private information. All they do is create an interface to a bitcoind instance that is exposed in such a way the Electrum client, which stores the important and private data, can read it. The only 'evil' thing an Electrum server could do is lying about certain transactions, feeding you misinformation. When you run your own ...


4

who store the private key adresses of these seed phrases, The private-keys are generated from the seed-phrase by a mathematical function. There is no need to store a list of seed-phrases and corresponding private-keys. I suppose it is the wallet software provider No, you should be the only person to know or store your seed-phrase. Ideally it should not ...


4

Trezor is a relatively simple, specialized hardware device. It does not run any OS, just a small program specifically developed for signing Bitcoin transactions and managing the keys. Thus, the attack surface is very small compared to conventional general-purpose computers. You can say it's practically impossible to infect it. Security is a much more ...


3

Mike Hearn talks in his speech about the future of bitcoin and mentions subchannels when doing micro payments, is this what you are looking after? When i try this in Testnet getreceivedbyaddress does show the amount sent to the multisig address, but listunspent does not. So even if listaddressgroupings include the multisig address, you still need to know ...


3

You simply can't add, insert or install software or any executable stuff into a Trezor. Due to the way the Trezor is set up, it runs fully autonomically. The only thing that goes into the Trezor is transaction details (addresses, amounts, etc). There's just no opportunity whatsoever to put any malware in there, because whatever you send to the Trezor, it's ...


3

Fraud and money laundering are two different things. Fraud, or accepting or spending money under false pretenses, would be very difficult to detect on the blockchain because it requires outside knowledge. The way banks detect fraud is by using the context of what was purchased, and where. The blockchain doesn't contain that information, so supplemental ...


3

To support timely settlement services outside an exchange's platform, around 1/12 to 1/16 value of an exchange's cryptocurrency value will probably need to be placed in hot storage. The rest will be in cold storage. Conceptually, fractional hot to cold storage ratios are analogous to fractional reserve banking and PBX trunk sizing. The cybersecurity ante ...


3

The private keys are not stored, they are deterministically generated from the seed data. The seed encodes up to 256 bits of random entropy in a human readable form with a checksum attached to it. These details are outlined in BIP39 This entropy is then passed through the PBKDF2 hash function in order to produce a master private key and a chaining key, ...


1

Unfortunately, good security isn't always easy. In this case, your worry is not unjustified, and it is why most security-conscious users will recommend never having privkeys touch an online device. This is, at minimum, required to mitigate against the sort of software-based attacks you've outline above. IF you have an online computer that holds privkeys and ...


1

The verification you are referring to applies to the installer file you downloaded. The verification instructions for Windows can be found here. The instructions for other operating systems are on the same page. Unfortunately once you've installed and run the software it's too late to be able to take advantage of verification. If the software was ...


1

The writer of that sentence did a poor job explaining things. A blockchain (the data structure) does not create a wallet. It is the data that a wallet uses to determine the state of the money it manages. It is also the data that new transactions are appended to, thus changing that state, and wallets submit those transactions. A blockchain does not create ...


1

security... TOR It is important to note that TOR does not provide added security. In fact, it could decrease security because you are funneling your traffic through exit nodes which could try to manipulate or log that traffic. TOR does however help with privacy because it helps hide your actual IP address and therefore location / identity. Running a full ...


1

Chainpoint is a standard for maximizing the scalability of recording data in the blockchain and generating blockchain receipts. Each receipt contains all the information needed to verify the data without relying on a trusted third party. You can read our white paper and download a Python implementation of a Chainpoint server at http://github.com/chainpoint. ...


1

I know one personally in Israel, https://bit2c.co.il it's Israeli bitcoin exchange.


1

first you have a misconception, BTCs are only stored in the blockchain, wallet.dat stores public/private keypairs of your addresses, addresses can have or not BTCs to spent but that's irrelevant for the storage. Bitcoin has nothing like a API for backups, but it does have encrypted wallets so you can encrypt your wallet file and you only will be able to use ...


1

You can use http://brainwallet.org to generate a so-called "Memory Wallet". Do not use the live website, download the sourcecode from github. How this works is you select a phrase, like "Correct Horse Battery Staple", and that phrase will consistently compute to a keypair you can use to store and later retrieve bitcoins. BE EXTREMELY CAREFUL, or maybe don'...


1

step 1 - memorize all the private keys that would otherwise be stored in some sort of wallet file step 2 - there is no step 2


1

Mt. Gox locks their Yubikeys with an access code. You cannot reprogram them without the code. If you're willing to wait a few months, you can brute force it.


1

What precautions should be taken to protect a Ripple wallet? You can keep your wallet offline most of the time. See this. You'll need to go online to check your balance or spend. Beyond that, I'd also advise you to only use the client while online with that computer. For Bitcoin, you can keep your wallet airgapped permanently with Armory, but I don't ...


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