Blockchain for beginners

A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a cryptographic hash of the previous block,a timestamp, and transaction data. By design, a blockchain is resistant to modification of the data. It is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way".

For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for inter-node communication and validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without alteration of all subsequent blocks, which requires consensus of the network majority.

Blockchains are secure by design and exemplify a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain. This makes blockchains potentially suitable for the recording of events, medical records,and other records management activities, such as identity management, transaction processing, documenting provenance, food traceability, and voting.

Blockchain was invented by Satoshi Nakamoto in 2008 to serve as the public transaction ledger of the cryptocurrency bitcoin.[1] The invention of the blockchain for bitcoin made it the first digital currency to solve the double-spending problem without the need of a trusted authority or central server. The bitcoin design has inspired other applications.

The first work on a cryptographically secured chain of blocks was described in 1991 by Stuart Haber and W. Scott Stornetta. They wanted to implement a system where documents' timestamps could not be tampered with or backdated. In 1992, Bayer, Haber and Stornetta incorporated Merkle trees to the design, which improved its efficiency by allowing several documents to be collected into one block.

The first blockchain was conceptualized by a person (or group of people) known as Satoshi Nakamoto in 2008. It was implemented the following year by Nakamoto as a core component of the cryptocurrency bitcoin, where it serves as the public ledger for all transactions on the network. Through the use of a blockchain, bitcoin became the first digital currency to solve the double-spending problem without requiring a trusted authority and has been the inspiration for many additional applications.

In August 2014, the bitcoin blockchain file size, containing records of all transactions that have occurred on the network, reached 20 GB (gigabytes). In January 2015, the size had grown to almost 30 GB, and from January 2016 to January 2017, the bitcoin blockchain grew from 50 GB to 100 GB in size.

The words block and chain were used separately in Satoshi Nakamoto's original paper, but were eventually popularized as a single word, blockchain, by 2016. The term blockchain 2.0 refers to new applications of the distributed blockchain database, first emerging in 2014.

The Economist described one implementation of this second-generation programmable blockchain as coming with "a programming language that allows users to write more sophisticated smart contracts, thus creating invoices that pay themselves when a shipment arrives or share certificates which automatically send their owners dividends if profits reach a certain level."

Blockchain 2.0 technologies go beyond transactions and enable "exchange of value without powerful intermediaries acting as arbiters of money and information." They are expected to enable excluded people to enter the global economy, protect the privacy of participants, allow people to "monetize their own information," and provide the capability to ensure creators are compensated for their intellectual property. Second-generation blockchain technology makes it possible to store an individual's "persistent digital ID and persona" and provides an avenue to help solve the problem of social inequality by "potentially changing the way wealth is distributed".

As of 2016, blockchain 2.0 implementations continue to require an off-chain oracle to access any "external data or events based on time or market conditions [that need] to interact with the blockchain."

Blocks hold batches of valid transactions that are hashed and encoded into a Merkle tree. Each block includes the cryptographic hash of the prior block in the blockchain, linking the two. The linked blocks form a chain. This iterative process confirms the integrity of the previous block, all the way back to the original genesis block.


Decentralization

By storing data across its peer-to-peer network, the blockchain eliminates a number of risks that come with data being held centrally. The decentralized blockchain may use ad-hoc message passing and distributed networking.

Peer-to-peer blockchain networks lack centralized points of vulnerability that computer crackers can exploit; likewise, it has no central point of failure. Blockchain security methods include the use of public-key cryptography. A public key (a long, random-looking string of numbers) is an address on the blockchain. Value tokens sent across the network are recorded as belonging to that address. A private key is like a password that gives its owner access to their digital assets or the means to otherwise interact with the various capabilities that blockchains now support. Data stored on the blockchain is generally considered incorruptible.

Every node in a decentralized system has a copy of the blockchain. Data quality is maintained by massive database replication and computational trust. No centralized "official" copy exists and no user is "trusted" more than any other.

Open blockchains are more user-friendly than some traditional ownership records, which, while open to the public, still require physical access to view. Because all early blockchains were permissionless, controversy has arisen over the blockchain definition. An issue in this ongoing debate is whether a private system with verifiers tasked and authorized (permissioned) by a central authority should be considered a blockchain.

The great advantage to an open, permissionless, or public, blockchain network is that guarding against bad actors is not required and no access control is needed. This means that applications can be added to the network without the approval or trust of others, using the blockchain as a transport layer.

Bitcoin and other cryptocurrencies currently secure their blockchain by requiring new entries to include a proof of work. To prolong the blockchain, bitcoin uses Hashcash puzzles. While Hashcash was designed in 1997 by Adam Back, the original idea was first proposed by Cynthia Dwork and Moni Naor and Eli Ponyatovski in their 1992 paper "Pricing via Processing or Combatting Junk Mail".


Uses

Blockchain technology can be integrated into multiple areas. The primary use of blockchains today is as a distributed ledger for cryptocurrencies, most notably bitcoin. While a few central banks, in countries and regions such as India, China, Hong Kong, United States, Sweden, Singapore, South Africa and the United Kingdom are studying issuance of a Central Bank Issued Cryptocurrency (CICC), none have done so as of 22 December 2016.

General potential

Blockchain technology has a large potential to transform business operating models in the long term. Blockchain distributed ledger technology is more a foundational technology—with the potential to create new foundations for global economic and social systems—than a disruptive technology, which typically "attack a traditional business model with a lower-cost solution and overtake incumbent firms quickly". Even so, there are a few operational products maturing from proof of concept by late 2016. The use of blockchains promises to bring significant efficiencies to global supply chains, financial transactions, asset ledgers and decentralized social networking.


Types of blockchains

Currently, there are three types of blockchain networks - public blockchains, private blockchains and consortium blockchains.

Public blockchains

A public blockchain has absolutely no access restrictions. Anyone with an internet connection can send transactions[disambiguation needed] to it as well as become a validator (i.e., participate in the execution of a consensus protocol). [149][self-published source?] Usually, such networks offer economic incentives for those who secure them and utilize some type of a Proof of Stake or Proof of Work algorithm.

Some of the largest, most known public blockchains are Bitcoin and Ethereum.


Private blockchains

A private blockchain is permissioned. One cannot join it unless invited by the network administrators. Participant and validator access is restricted.

This type of blockchains can be considered a middle-ground for companies that are interested in the blockchain technology in general but are not comfortable with a level of control offered by public networks. Typically, they seek to incorporate blockchain into their accounting and record-keeping procedures without sacrificing autonomy and running the risk of exposing sensitive data to the public internet.


Consortium blockchains

A consortium blockchain is often said to be semi-decentralized. It, too, is permissioned but instead of a single organization controlling it, a number of companies might each operate a node on such a network. The administrators of a consortium chain restrict users’ reading rights as they see fit and only allow a limited set of trusted nodes to execute a consensus protocol.

Lower temps at a lower price: How to improve the energy-efficiency of your home today

When the seasons change, the energy needs in your home change right along with them. And yet, whether you need to heat or cool your home, there's one thing that never shifts: You want to do so as efficiently as possible.

An energy-efficient home is more than just good for the environment. It's good for your pocketbook as well. By eliminating any unnecessary energy expenses you ensure you have more money to spend enjoying all the season has to offer.

You can start making your home more energy-efficient today and it begins with these four tips.

* Get proactive about your insulation. Your home's insulation is often treated with an out-of-sight, out-of-mind mentality, yet improvements here could dramatically support your home's energy-efficiency. While insulation is commonly seen as a benefit to keep your home warm in the winter, it also works to keep cool, air-conditioned air inside as well. Your insulation needs depend, in part, on where you live, but it's worth your time to research this opportunity. Check to see that you have sufficient insulation and make additions or replacements as necessary.

* Bring your windows into focus. The role your windows have in dictating the temperature in your home can be considerable. Older windows allow cool air to escape outside and that makes your air conditioner work harder to control the interior temperature. Replacing them eliminates this problem and sets you up to more easily retain heat during the winter. And if new windows simply aren't possible right now, you can also make a smaller, more immediate impact on your energy-efficiency by closing the curtains during peak sunlight hours. This helps keep the temperature of your home cooler and reduces stress on your unit.

* Consider alternative energy sources. Instead of simply focusing on what you can do with your current energy situation, expand your options to alternative energy sources as well. Installing home solar panels can drastically cut or even eliminate your electricity bills and even increase your home's resale value. Newer systems maximize sunlight absorption and generate the maximum possible output - as much as 26 percent more than other comparably sized solar panels. This higher efficiency means that your solar panels can work in any climate or season to deliver for you.

If you buy an AC with a lower than required capacity—measured in tonnage—it will consume a lot more energy to provide the requisite cooling. Lower capacity units may save you on capital cost, but it will increase the electricity consumption and also decrease the life span of the device.

If you buy an AC with a higher than required capacity, you will end up paying more for the purchase, besides getting large power bills.


Energy efficiency ratings

To help you buy energy-efficient ACs, Bureau of Energy Efficiency (BEE) in 2016 came up with a new rating methodology, ISEER (Indian Seasonal Energy Efficiency Ratio) Ratings, which are better and stringent. Higher the star ratings of an AC, lesser the power it consumes. This, however, does not mean that you should always go for a 5-star rated AC, say experts.

The decision should mainly be based on your usage pattern. If you are going to run the AC for few hours daily, then a 3-star rated AC is good enough. Also, lower star-rated ACs usually have higher air circulation rate, so your room cools faster. Experts suggest that only if your AC usage is over eight hours do you need the costlier but less power consuming 5-star rated AC, to make a worthwhile difference to your electricity bill.

After-sales service Much like cars, ACs need regular servicing for optimum performance. So, one of the things you need to keep in mind before buying an AC is the company’s aftersales service, and warranty. A little research will throw up names of the best and the worst service providers. Choose appropriately.

Unlocking amino acid potential and building lean muscle

While the global protein category is nearing $6 billion annually, there are many conflicting theories and reports about the best combination of ingredients for success as it relates to building muscle. In addition, many consumers are easily confused by the wide variety of products available to them at any given time.

Being able to choose the right supplement always starts with a solid understanding of the fundamentals of amino acids and knowing what you need to successfully build muscle.


Amino Acids 101

Amino acids are critical to supporting muscle growth and strength. A common misconception is that Branch Chain Amino Acids (BCAAs), isoleucine, leucine and valine alone can build lean muscle. But in fact, the body needs all nine essential amino acids (EAAs), histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine and valine in order to build muscle.

In general, an effective way to help build muscle is to consume these EAAs, commonly found in protein powders, in connection with a healthy diet and weight/resistance program. Such protein powders consist of a variety of EAAs that have been shown to aid in muscle building.


Supplements that provide the "full package"

When combined with a balanced diet and consistent training in weight/resistance programs, well-rounded supplements containing all nine EAAs allow consumers to take their workouts to the next level. Solutions such as the XS(TM) Muscle Multiplier EAA Supplement (when combined with regular weight/resistance training and a healthy balanced diet), leverage a blend of EAAs to assist in building lean muscle. Developed by a leading expert on essential amino acids and protein synthesis, XS(TM) Muscle Multiplier Essential Amino Acid Supplement contains the exact compositions and ratio of all nine essential amino acids necessary to help build lean muscle.

The formula delivers 3.6 grams of EAAs in a blend patented to assist in building lean muscle when combined with regular weight/resistance training and a healthy balanced diet. The recommended use is to consume 1-3 servings per day, before, during or after exercise or in between meals.

Unlike BCAAs alone, this solution uses 35 percent leucine, 20 percent lysine and 15 percent valine, with the remaining amino acids (histidine, isoleucine, methionine, phenylalanine and threonine) in an additional 30 percent.


Looking to the future

Although the protein category has remained largely unchanged throughout the past 40 years, solutions like the XS(TM) Muscle Multiplier Essential Amino Acid Supplement have the potential to reignite long-awaited innovation in the growing sports nutrition market.

As active generations seek to educate themselves on the benefits of essential amino acids, they will continue to further master the proper way to work out and supplement those workouts. It is simply a matter of building a strong understanding of how the body works and what can be done to help sustain its overall wellness.

Take control of your social media experience in 3 easy steps

Does all this talk about data and sharing on social media have you confused? Is your feed too noisy and you're not seeing posts from the people and brands you care about? Social media should be a fun place for you to have meaningful interactions with friends and family. Here are three simple steps to block the distractions and have more control over your social media experience.

See what you want, hide what you don't 

On Facebook, take a peek at Pages, Groups and friends that you follow. Do you still need to follow the TV show that was cancelled in 2011, or cricket scores of matches played in the 1980s? If the answer is no, you can:

* Unfollow: When you unfollow a person, Page or Group, you won't see their posts in your News Feed, but in the case of your friends, you'll still be friends with them.

* Hide Post: Hiding a single post gives you the option to see fewer posts from a specific person, Page or Group.

* Snooze: When you temporarily snooze a person, Page, or Group, you won't see their posts in your News Feed for the amount of time you select.

* See First: When you select a person or Page to see first, their posts appear at the top of your News Feed. The entity won't know you selected them.

* Unfriend: If you unfriend someone, you'll be removed from that person's friends list as well. If you want to be friends with this person again, you'll need to add them as a friend again. The person you unfriended won't be notified.


Make your settings do the work

Want more information on the ads you see? Want to make your profile more private? Here are a few security and privacy control tips for Facebook:

Security settings:

* Click the menu button on the bottom right-hand corner and scroll down to Privacy Shortcut.

* From there make all the decisions yourself! See who is able to send you friend requests and view photos you're tagged in, and adjust any of those settings.

* Do a Privacy Checkup and review all the third-party apps you've used Facebook to log into, and choose to disconnect if you like.

* Privacy Checkup also has tutorials on how to use all major privacy controls.

Ad preferences:

* Click the menu button on the bottom right-hand corner and scroll down to Settings. Click Account Settings and then scroll down to Ads. This helps you manage ads you see to make them more relevant to you.

* You're able to see what advertisers you've interacted with, view your interests and discover new ones that you'd like to receive ads around such as "beauty" or "arts and music," and hide any topics you do not wish to interact with.

* On Instagram, click the top right-hand button on an ad to hide it, which will help determine which ads you see in the future.


Final touch-up

Make sure your social media is the best representation of you.

Make yourself recognizable and say goodbye to outdated pics. Click on Edit Profile under your Profile picture - did you recently go through a major life change? Move to a new city? Relationship status switch to "taken?" Make sure the information you want to share is up-to-date.