background preloader

How the Bitcoin protocol actually works

How the Bitcoin protocol actually works
Many thousands of articles have been written purporting to explain Bitcoin, the online, peer-to-peer currency. Most of those articles give a hand-wavy account of the underlying cryptographic protocol, omitting many details. Even those articles which delve deeper often gloss over crucial points. My aim in this post is to explain the major ideas behind the Bitcoin protocol in a clear, easily comprehensible way. We’ll start from first principles, build up to a broad theoretical understanding of how the protocol works, and then dig down into the nitty-gritty, examining the raw data in a Bitcoin transaction. Understanding the protocol in this detailed way is hard work. I’ll describe Bitcoin scripting and concepts such as smart contracts in future posts. It may seem surprising that Bitcoin’s basis is cryptography. My strategy in the post is to build Bitcoin up in stages. This strategy is slower than if I explained the entire Bitcoin protocol in one shot. First steps: a signed letter of intent

Powershell – Get locked out AD user accounts and export to CSV – Noam's scripting blog $scriptpath = $MyInvocation.MyCommand.Path $dir = Split-Path $scriptpath $after = (get-date).addHours(-1) $lockoutEventID = 4740 $DC = "SomeDC" function Get-LockoutEvents { param( $after, $lockoutEventID, $computerName = $env:COMPUTERNAME $lockoutEvents = @(Get-EventLog -LogName "Security" -After $after -ComputerName $computerName | Where-Object {$_.EventID -eq $lockoutEventID}) return $lockoutEvents function Parse-LockoutEvent { $lockoutEvent $EventTxt = $lockoutEvent.Message $bool = $EventTxt -match "(.*?) $lockoutUser = $Matches[3] $lockoutTime = $lockoutEvent.TimeGenerated $lockoutSource = $lockoutEvent.Source $lockoutMessage = $lockoutEvent.Message -creplace "`n|`r","" $lockoutMessage = $lockoutMessage -creplace "`t"," " $lockout = "" | select "User","Time","Source","Message" $lockout.User = $lockoutUser $lockout.Time = $lockoutTime $lockout.Source = $lockoutSource $lockout.Message = $lockoutMessage Return $lockout function ExportToFile-LockoutEvents { $lockouts $fileName = "$dir\Lockouts--$datestr.csv"

What bitcoin needs next: education and an ecosystem, says Marc Andreessen Since its introduction in 2009, bitcoin’s had a bumpy ride — and that should come as no surprise. According to Netscape founder Marc Andreessen, ongoing press controversies over bitcoin amount to growing pains, and are akin to the media coverage he saw during the early days of the Internet. “You don’t get new technologies from the mainstream. During a panel appearance with Balaji Srinivasan, also a partner Andreessen Horowitz, the two venture capitalists discussed the growing ecosystem of bitcoin — and where they are looking to invest. “We think of it potentially on the scale of the Internet. Marc Andreessen with Balaki Srinivasan and moderator Kashmir Hill from Forbes. Right now, Srinivisan said he views the cryptocurrency as an inverted pyramid, with lots of news coverage on top but very few people working on the code and developing on the bottom. “I think there are very few things that are going to grow like bitcoin consulting in the next few years,” Srinivisan said.

Antivirus companies cause a big headache to small developers. Antivirus is essential tool that most people need to protect their Windows operating system from Viruses, Trojans, and other bad stuff. Unfortunately, most Antivirus companies goes too far with their Virus/Trojan protection, and in many times they classify completely legit software as Virus/Trojan infection.One good example for that is my own password recovery tools: Most people need these tools to recover their own lost password. These password tools, like many other utilities out there, can also be used by hackers for bad purposes.The attitude of many Antivirus companies is very tough in this subject -If it's a tool that can be used by bad guys, it's classified as Trojan or Virus, even when most users need it and use it for good purposes. My password-recovery utilities are not the only victims of the "over protection" made by Antivirus software. Other developers also have "False Positive" problems What about large companies like Microsoft ? Examples for emails I receive on daily basis

I analyzed more than a million bitcoin tweets. Here’s what that looks like I recently got my hands on more than 1.3 million tweets, all mentioning bitcoin or creator Satoshi Nakamoto, spanning the entire month of February 2014. My goal was to get a sense of who’s actually interested in bitcoin (enough to tweet about it, at least) and to see how activity on Twitter tracked with big news stories. Here’s what I found. Click on any image for a larger version. (Disclaimer: I’m neither a statistician nor a programmer, so I used relatively simple tools for analysis and worked with companies on other aspects. Who’s tweeting about Bitcoin All told, 333,144 unique accounts posted messages related to bitcoin. Here are the 10 usernames that received the most @ mentions. Some were one-hit wonders with massively retweeted posts, such as talk show host Conan O’Brien. And someone called Bacon Bangkok. I filtered out one account that’s still active but generated in about an hour more than 4,400 spammy retweets of a post, now removed, about opening a free bitcoin wallet. The Mt.

windows - Locking a Computer Down to only one website? How to Buy Bitcoins Zabezpieczenie Wordpressa przed atakami brute force. Zabezpieczenie Wordpressa przed atakami brute force. Dodano: 2017-01-17 Atak brute force na stronę opartą o popularny system Wordpress wykonać może nawet średnio rozgarnięty dzieciak - wystarczy, że znajdzie odpowiedni skrypt w internecie i sciagnie do niego odpowiednio dużą bazę haseł. Atak brute force to próba włamania poprzez próbę odganięcia loginów i haseł do witryny. Oprócz oczywistego problemu włamania na stronę problemem jest także jej przeciążanie - intruz z reguły dokonuje kilku prób odganięcia hasła na raz przez co Twoja witryna może być niedostepna. Przy odpowiednio silnym łączu zgadnięcie hasła bywa kwestią czasu - dlatego tak ważny jest punkt pierwszy czyli... 1. Jeżeli Twoja dziewczyna ma na imię Angelika i urodziła się w roku 1986 ustawienie jej imienia i daty urodzin jako hasła nie jest dobrym pomysłem. Na temat tego czym jest trudne do zgadnięcia hasło napisano sporo elaboratów. 2. 3. Instalujemy plugin standardowo - klikamy Wtyczki -> Dodaj nową. Spodobał Ci się wpis?

Dans la section 1 j'ai choisi trois pages ... qui explique... What is the best way to detect a handheld device in jQuery? Dansla section 2 j'ai choisi des articles .. qui explique... Mark's Blog Index Scareware, a type of malware that mimics antimalware software, has been around for a decade and shows no sign of going away. The goal of scareware is to fool a user into thinking that their computer is heavily infected with malware and the most convenient way to clean the system is to pay for the… A key part of any cybersecurity plan is “continuous monitoring”, or enabling auditing and monitoring throughout a network environment and configuring automated analysis of the resulting logs to identify anomalous behaviors that merit investigation. This is part of the new “assumed breach” mentality that recognizes no system is 100% secure. Windows Azure’s compute platform, which includes Web Roles, Worker Roles, and Virtual Machines, is based on machine virtualization. This case is my favorite kind of case, one where I use my own tools to solve a problem affecting me personally. Many of you have read Zero Day, my first novel.