Knowledge Base

Coin Hour Bank

A System that stores Coin Hours in an address owned by Skycoin and allows users to transact Coin Hours off-chain without incurring a Coin Hour burn, whereby preventing the congestion of the blockchain.

Coin Hours

Accrued by holding Skycoin, Coin Hours are the payment mechanism for services on the Skycoin platform.

Skycoin, along with other Fiber tokens generate Coin Hours. SKY Hours for Skycoin specifically.


CoinJoin is a protocol for joining together transactions from different wallets and thereby allows sending CoinHours without sending Skycoin. It can also be used for anonymising transactions.

Cold Storage

Bitcoin Wiki Entry

Cold storage

Cold storage in the context of Bitcoin refers to keeping a reserve of Bitcoins offline. This is often a necessary security precaution, especially dealing with large amounts of Bitcoin.

For example, a Bitcoin exchange typically offers an instant withdrawal feature, and might be a steward over hundreds of thousands of Bitcoins. To minimize the possibility that an intruder could steal the entire reserve in a security breach, the operator of the website follows a best practice by keeping the majority of the reserve in cold storage, or in other words, not present on the web server or any other computer. The only amount kept on the server is the amount needed to cover anticipated withdrawals.

Methods of cold storage include keeping bitcoins:

Potential problems with cold storage methods exist but can be mitigated.

There are a number of cases where secret/private keys and/or backup seeds can be lost because of the medium on which they are stored. The the more common mediums of cold storage are listed with some of their weaknesses.

Written on a piece of paper:

  • Anyone who can see it, can steal it
  • Handwriting can be hard to read or completely illegible
  • Human error in transcription can cause errors on end product
  • Paper can rot, be torn, burn, or be smoke damaged

Printed on a piece of paper:

  • Anyone who can see it, can steal it
  • Type of printer - non-laser printers can run if paper gets wet
  • Have to trust printer - some have internet connections, wifi, and memory
  • Paper can rot, be torn, burn, or be smoke damaged

On laminated paper:

  • Anyone who can see it, can steal it
  • Lamination is prone or degradation over time and puncture or cuts that could allow moisture to get trapped in the paper and cause deterioration or rotting in some circumstances - store in cool dry place
  • Can burn or be smoke damaged
  • 'Fireproof' & 'Fire-resistant' boxes can help protect paper in a small house fire but be warned that they can sometimes fall apart in the fire and get wet if the fire is put out with water. * Remember people can just carry out a small safe.

Engraved / etched/ ablated/ stamped on a piece of metal:

  • Anyone who can see it, can steal it
  • Some metals can deteriorate or corrode, choose a good metal; also store your metal away from direct contact other metals. Some metals that are corrosion resistant have low melting points, are extremely expensive, or hard to machine.
  • Metals can still deform or melt from heat, destroying any engraved SK. "Most house fires do not burn hotter than 1,200 degrees Fahrenheit. This temperature is typically associated with the hottest portion of a home, which is in the roof area. Homes that burn for longer than 30 minutes or consist of multiple levels sometimes burn at higher temperatures."
  • You want to pick a metal that won't be destroyed by a fire. So magnesium, tin, and lead are all out as engraving materials.

Silver, gold, copper, brass, bronze, nickel, cobalt, would survive the housefire fire unmelted. Some Aluminium alloys can survive but you have to have the right ones. At around 1500° Steel and Nickel should be okay. Titanium is above the housefire range and so is tungsten, however tungsten rings are known to shatter due to the brittle nature of the very hard metal.

Stored digitally on a computer:

  • Computers can crash, making data recovery expensive
  • Data can still technically be recovered after a system is abandoned by the user. In some cases data can be recovered after multiple overwriting attempts and physical destruction (as long as the attacker can get all or most the pieces) so if you copy files to a new computer and ditch the old one, be careful.
  • Can burn or be smoke damaged
  • A traditional hard disc drive can have data corrupted by powerful magnetic fields and can physically shatter
  • A non-negligible amount of HDDs suffer from factory defects that will cause them to fail unexpectedly during their lifetime
  • Accidents can happen that could result in loss of data
  • Solid state drives (SSDs) will lose data if unpowered, they may last years before this becomes a problem but it is unwise to store long-term data in unpowered SSDs
  • If connected to internet it is another attack vector and the safety is only as good as the encryption used; I don't know what I would recommend but it wouldn't be BitLocker. Someone could be trying to break into the computer constantly. Even with good encryption if the machine or location is compromised the key could be stolen as soon as it is decrypted.
  • There are a lot of ongoing threats with computers, from 0-day exploits to firmware exploits and malicious USB cords
  • External hdds are good for storage for a few years at least if stored properly
  • If not connected to internet, safety is only as good as the physical protection encryption used; could someone break into the location and copy the data without anyone noticing?

Stored digitally on CD, floppy disk, laserdisc, or mini-disc

  • Plastics break down over time and with exposure to heat, humidity, regular light, all sorts of chemicals, even the oxygen in the air. This can lead to the loss of your data when stored on a medium made of plastic or written/printed on plastic.
  • Can burn or be smoke damaged
  • Can be physically damaged, making data recovery expensive or even impossible
  • Magnetic media (tapes, floppy disc) can be damaged by magnets
  • Data can become difficult to recover if the software and/or hardware to decode is old, don't use proprietary formats

Stored digitally on a flash drive

  • Can break and have to be physically repaired before use
  • Rapidly changing magnetic fields (See MRIs) can damage the data stored on flash drives
  • Can burn or be smoke damaged
  • Can become corroded from salt water or some atmospheric conditions
  • If they break apart, some lighting conditions can cause data corruption (you can also put them back together and often still get the data)
  • Different devices are all different, even similar devices from the same production batch can be different. There are large quality differences in drives but I am assuming you aren't using these for anything but storage.
  • There are some fake flash drives that look like they saved the data but you can't get it back later
  • Flash drives are not advised for long term storage; they can be used as one part of a multi-medium-location-format plan.

A pre-funded physical bitcoin coin (where the manufacturer generates and installs the secret key)

  • The medium that the key is on is often paper/plastic which can burn or be smoke damaged
  • Trust in the manufacturer themselves, they could copy the key
  • Trust in their key generation procedure
  • Trust in the operational security of the manufacturer, they could be generating the keys on their everyday computer
  • Trust no one is successfully spying on them, electronically, looking through their documents while they are out of town, or with tiny tin foil hat cameras or long range ones
  • Trust that the object was not tampered with in delivery
  • Trust that no one has tampered with the object since you got it

---Deep cold storage refers to keeping a reserve of Bitcoins offline, using a method that makes retrieving coins from storage significantly more difficult than sending them there. This could be done for safety's sake, such as to prevent theft or robbery.

Because Bitcoins can be sent to a wallet by anyone knowing the wallet address, it is trivial to put a wallet in cold storage but to keep a copy of the addresses needed to send funds to it.

A simple example of deep cold storage is opening a safe deposit box and putting a USB stick containing an encrypted wallet file in it. The public (sending) addresses can be used any time to send additional bitcoins to the wallet, but spending the bitcoins would require physical access to the box (in addition to knowledge of the encryption password).

Deep cold storage would typically be used for holding large amounts of bitcoins, or for a trustee holding bitcoins on behalf of others. In such a case, additional precautions should be taken beyond a simple example of a single safe deposit box.

  • The box could be accessed by bank or maintenance personnel, so the contents of the box alone should not be sufficient to access the wallet.
  • The box could be stolen or destroyed in a disaster, or the media could become unreadable, so the box should not contain the only copy of the wallet.
  • The trustee could die or become incapacitated. If access to the wallet or knowledge of its location is lost, or encryption passwords are lost, the bitcoins are gone forever. Provisions should be made so that the box can be accessed by someone else as appropriate, including any encryption passwords.

See also

Cryptocurrency Wallet

Wikipedia Entry

Cryptocurrency wallet

An example paper printable bitcoin wallet consisting of one bitcoin address for receiving and the corresponding private key for spending.

A cryptocurrency wallet is a device,[1] physical medium,[2] program or a service which stores the public and/or private keys and can be used to track ownership, receive or spend cryptocurrencies.[3] The cryptocurrency itself is not in the wallet. In case of bitcoin and cryptocurrencies derived from it, the cryptocurrency is decentrally stored and maintained in a publicly available ledger called the blockchain.[3]


A cryptocurrency wallet, comparable to a bank account, contains a pair of public and private cryptographic keys. A public key allows for other wallets to make payments to the wallet's address, whereas a private key enables the spending of cryptocurrency from that address.[4]

Wallet types

Wallets can either be digital apps or be hardware based.[5] They either store the private key with the user, or the private key is stored remotely and transactions are authorized by a third party.

An actual bitcoin transaction from a web based cryptocurrency exchange to a hardware wallet.

Multisignature wallet

Multisignature wallets require multiple parties to sign a transaction for any digital money can be spent.[6] Multisignature wallets are designed to have increased security.[7]

Key derivation

Deterministic wallet

With a deterministic wallet a single key can be used to generate an entire tree of key pairs.[8] This single key serves as the root of the tree. The generated mnemonic sentence or word seed is simply a more human-readable way of expressing the key used as the root, as it can be algorithmically converted into the root private key. Those words, in that order, will always generate exactly the same root key. A word phrase could consist of 24 words like: begin friend black earth beauty praise pride refuse horror believe relief gospel end destroy champion build better awesome. That single root key is not replacing all other private keys, but rather is being used to generate them. All the addresses still have different private keys, but they can all be restored by that single root key. The private keys to every address it has and will ever give out can be recalculated given the root key. That root key, in turn, can be recalculated by feeding in the word seed. The mnemonic sentence is the backup of the wallet. If a wallet supports the same (mnemonic sentence) technique, then the backup can also be restored on another software or hardware wallet.

A mnemonic sentence is considered secure. The BIP-39 standard creates a 512-bit seed from any given mnemonic. The set of possible wallets is 2512. Every passphrase leads to a valid wallet. If the wallet was not previously used it will be empty.[3]:104

Non-deterministic wallet

In a non-deterministic wallet, each key is randomly generated on its own accord, and they are not seeded from a common key. Therefore, any backups of the wallet must store each and every single private key used as an address, as well as a buffer of 100 or so future keys that may have already been given out as addresses but not received payments yet.[3]:94

See also


  1. ^ Roberts, Daniel (15 December 2017). "How to send bitcoin to a hardware wallet". Yahoo! Finance. Retrieved 11 March 2019.
  2. ^ Divine, John (1 February 2019). "What's the Best Bitcoin Wallet?". U.S. News & World Report. Retrieved 12 March 2019.
  3. ^ a b c d Antonopoulos, Andreas (12 July 2017). Mastering Bitcoin: Programming the Open Blockchain. O'Reilly Media, Inc. ISBN 9781491954386. Retrieved 14 September 2017.
  4. ^ "Bitcoin Wallets: What You Need to Know About the Hardware". The Daily Dot. 2018-11-20. Retrieved 2019-03-10.
  5. ^ Newman, Lily Hay (2017-11-05). "How to Keep Your Bitcoin Safe and Secure". Wired. ISSN 1059-1028. Retrieved 2019-03-10.
  6. ^ "Bitcoin Startup Predicts Cryptocurrency Market Will Grow By $100 Billion in 2018". Fortune. Retrieved 2019-02-15.
  7. ^ Graham, Luke (2017-07-20). "$32 million worth of digital currency ether stolen by hackers". Retrieved 2019-02-15.
  8. ^ Gutoski, Gus; Stebila, Douglas. "Hierarchical deterministic Bitcoin wallets that tolerate key leakage" (PDF). International Association for Cryptologic Research. Retrieved 2 November 2018.


The Next Generation Blockchain Programming Language


CX is a general purpose, interpreted and compiled programming language, with a very strict type system and a syntax similar to Golang’s. CX provides a new programming paradigm based on the concept of affordances, where the user can ask the programming language at runtime what can be done with a CX object (functions, expressions, packages, etc.), and interactively or automatically choose one of the affordances to be applied. This paradigm has the main objective of providing an additional security layer for decentralized, blockchain-based applications, but can also be used for general purpose programming.



The splinternet (also referred to as cyber-balkanization, cyber-balkanisation, internet balkanization, or internet balkanisation) is a characterization of the Internet as splintering and dividing due to various factors, such as technology, commerce, politics, nationalism, religion, and interests. "Powerful forces are threatening to balkanise it", writes the Economist weekly, and it may soon splinter along geographic and commercial boundaries.[1] Countries such as China have erected what is termed a "Great Firewall", for political reasons, while other nations, such as the US and Australia, discuss plans to create a similar firewall to block child pornography or weapon-making instructions.[1]

Clyde Wayne Crews, a researcher at the Cato Institute, first used the term in 2001 to describe his concept of "parallel Internets that would be run as distinct, private, and autonomous universes."[2] Crews used the term in a positive sense, but more recent writers, like Scott Malcomson, a fellow in New America's International Security program, use the term pejoratively to describe a growing threat to the internet's status as a globe-spanning network of networks.[3]


Describing the splintering of Internet technology, some writers see the problem in terms of new devices using different standards. Users no longer require web browsers to access the Internet, as new hardware tools often come with their own "unique set of standards" for displaying information.[4]

Journalist and author Doc Searls uses the term "splinternet" to describe the "growing distance between the ideals of the Internet and the realities of dysfunctional nationalisms...", which contribute to the various, and sometimes incompatible standards which often make it hard for search engines to use the data. He notes that "it all works because the Web is standardized. Google works because the Web is standardized". However, as new devices incorporate their own ad networks, formats, and technology, many are able to "hide content" from search engines".[5]

Others, including information manager Stephen Lewis, describe the causes primarily in terms of the technology "infrastructure", leading to a "conundrum" whereby the Internet could eventually be carved up into numerous geopolitical entities and borders, much as the physical world is today.[6]

Commercial lock-in

The Atlantic magazine speculates that many of the new "gadgets have a 'hidden agenda' to hold you in their ecosystem". Writer Derek Thomson explains that "in the Splinternet age, ads are more tightly controlled by platform. My old BlackBerry defaulted to Bing search because (network operator) Verizon has a deal with Microsoft. But my new phone that runs Google Android software serves Google ads under apps for programs like Pandora". They rationalize the new standards as possibly a result of companies wishing to increase their revenue through targeted advertising to their own proprietary user base. They add, "This is a new age, where gadgets have a 'hidden agenda' to hold you in their ecosystem of content display and advertising. There are walls going up just as the walls to mobile Internet access are falling down".[7]

Forrester Research vice president and author Josh Bernoff also writes that "the unified Web is turning into a Splinternet", as users of new devices risk leaving one Internet standard. He uses the term "splinternet" to refer to "a web in which content on devices other than PCs, or hidden behind passwords, makes it harder for site developers and marketers to create a unified experience".[8] He points out, for example, that web pages "don't look the same because of the screen size and don't work the same since the iPhone doesn't support Flash". He adds that now, with the explosion of other phone platforms like Google Android, "we'll have yet another incompatible set of devices".[9] However, both Android and iOS are Unix-based platforms, and both offer WebKit-based browsers as standard, as does handset manufacturer Nokia.[10]

Politics and nationalism

A survey conducted in 2007 by a number of large universities, including Harvard, found that Iran, China, and Saudi Arabia filter a wide range of topics, and also block a large amount of content related to those topics. South Korea filters and censors news agencies belonging to North Korea.[11]

It found that numerous countries engaged in "substantial politically motivated filtering", including Burma, China, Iran, Syria, Tunisia, and Vietnam. Saudi Arabia, Iran, Tunisia, and Yemen engage in substantial social content filtering, and Burma, China, Iran, Pakistan and South Korea have the most encompassing national security filtering, targeting the websites related to border disputes, separatists, and extremists.[11]

Foreign Policy writer, Evgeny Morozov, questions whether "the Internet brings us closer together", and despite its early ideals that it would "increase understanding, foster tolerance, and ultimately promote worldwide peace", the opposite may be happening.[12] There are more attempts to keep foreign nationals off certain Web properties, for example, digital content available to U.K. citizens via the BBC's iPlayer is "increasingly unavailable to Germans". Norwegians can access 50,000 copyrighted books online for free, but one must be in Norway to do so.[12] As a result, many governments are actively blocking Internet access to its own nationals, creating more of what Morozov calls a "Splinternet":

Google, Twitter, Facebook — are U.S. companies that other governments increasingly fear as political agents. Chinese, Cuban, Iranian, and even Turkish politicians are already talking up "information sovereignty" a euphemism for replacing services provided by Western Internet companies with their own more limited but somewhat easier to control products, further splintering the World Wide Web into numerous national Internets. The age of the Splinternet beckons.[12]

Organizations such as the OpenNet Initiative were created because they recognized that "Internet censorship and surveillance are growing global phenomena." Their book on the subject was reportedly "censored by the U.N." with a poster removed by U.N. security officials because it mentioned China's "Great Firewall".[13] In March 2010, Google chose to pull its search engines and other services out of China in protest of their censorship and the hacking of Gmail accounts belonging to Chinese activists.[14]

Other countries, besides China, also censor Internet services: Reporters Without Borders ranks Iran's press situation, for example, as "Very serious", the worst ranking on their five-point scale.[15] Iran's Internet censorship policy is labeled "Pervasive" by the OpenNet Initiative's global Internet filtering map, and the worst in the ranking.[16] In March 2010, they added Turkey and Russia to their 'under surveillance' list regarding Internet censorship, and warned other countries, such as the United Arab Emirates, Belarus and Thailand, also "under surveillance" status, to avoid getting transferred into the next "Enemies of the Internet" list.[17]

Security and espionage

In May 2013, former United States CIA and NSA employee Edward Snowden provided The Guardian with documents revealing the existence of far-reaching espionage systems installed by the NSA at critical junctions where Internet traffic is aggregated. As various world governments have learned the extent to which their own communications have been compromised, concerns have been raised that these governments will erect sovereign networks so as to isolate their traffic from NSA spying programs.[18]

In October 2013, Brazilian President Dilma Rouseff announced plans to create a "walled-off, national Intranet".[19][20]


Internet access has also been blocked for reasons of religion. In 2007, and again in May 2010, Pakistan reportedly blocked Facebook, YouTube, Google, and Wikipedia, to contain what it described as "blasphemous" and "un-Islamic" material.[21][22]

The Church of Scientology recommended Internet censorship as a method of defending itself against what it said were a constant campaign of abuse by the group "Anonymous", along with "misinformation" and "misrepresentation" in the media. In September 2009 it asked the Australian Human Rights Commission's Freedom of Religion and Belief to restrict access to web sites it believes incites "religious vilification."[23]


Splintering of the Internet community can occur when members of specific interest groups use the Internet to exclude or avoid views that contradict their own cherished beliefs and theories. Called Cyberbalkanization (or sometimes cyber-balkanization), it refers to the division of the Internet or the world wide web into sub-groups with specific interests (digital tribes), where the sub-group's members almost always use the Internet or the web to communicate or read material that is only of interest to the rest of the sub-group. The term may have first been used in an MIT paper by Marshall Van Alstyne and Erik Brynjolfsson that was published in late 1996.[24] The concept was also discussed in a related article in the journal Science that same year.[25] The term is a hybrid of cyber, relating to the Internet, and Balkanization, a phenomenon that takes its name from the Balkans, a part of Europe that was historically subdivided by languages, religions and cultures.

In his 2001 book, Cass Sunstein argued that cyberbalkanization could damage democracy, because it allows different groups to avoid exposure to one another as they gather in increasingly segregated communities, making recognition of other points of view or common ground decreasingly likely. The commentator Aleks Krotoski feels that Jihadist groups often use the Internet in this way.[26]

Despite the concerns of cyberbalkanization, there is mixed evidence that it is actually growing. One Wharton study found that internet filters can create commonality, not fragmentation. However, this study primarily focused on music recommendation algorithms, and openly states that more research is required surrounding other domains (e.g. news, books, fashion).[27] Another study found that ideological segregation of online news consumption is low in absolute terms, higher than the segregation of most offline news consumption, and significantly lower than the segregation of face-to-face interactions with neighbors, co-workers, or family members. The study notes that an important caveat, however, is that none of their evidence speaks to the way people translate the content they encounter into beliefs, which may be a larger factor in the problem these types of studies seek to address.[28]

See also


  1. ^ a b "A virtual counter-revolution" The Economist, 2010-09-02
  2. ^ Libertarian, or Just Bizarro?, Aparna Kumar, WIRED
  3. ^ "Welcome to the Splinternet Malcomson, Scott. Techonomy, 2015-12-22
  4. ^ "Splinternet? Growing Variety of Devices Presents Content Challenge", 2010-01-27
  5. ^ Doc Searls, "The Splinternet" 2008-12-16
  6. ^ "appliancing"-of-national-boundaries/ "The Internet and Its Infrastructure" 2008-12-08
  7. ^ "The Fall of the Internet and the Rise of the 'Splinternet'". The Atlantic. 2010-03-08.
  8. ^ "The Splinternet War: Apple vs. Google vs. Facebook" Advertising Age, 2010-04-30
  9. ^ "The Web Is Turning Into The 'Splinternet'" Bernoff, Josh. Forbes, 2010-03-29
  10. ^ "Nokia Open Source". Nokia Developer. Nokia. Retrieved 2011-08-11.
  11. ^ a b "Survey of Government Internet Filtering Practices Indicates Increasing Internet Censorship". Berkman Center, Harvard University. 2007-05-18.
  12. ^ a b c Morozov, Evgeny. Think Again: The Internet" Foreign Policy, May/June 2010
  13. ^ "FAQ: What Happened at the Internet Governance Forum?". OpenNet Initiative. 2008-11-15.
  14. ^ "Don't Be Evil". The New Republic. 2010-04-21.
  15. ^ "Reporters Without Borders - Iran". Archived from the original on 2009-07-06.
  16. ^ "ONI Internet Filtering Map".
  17. ^ "Bianet: Internet Censorship: Turkey "Under Surveillance" Of RSF", 2010-03-15
  18. ^ Naughton, John. "Edward Snowden's not the story. The fate of the internet is". The Guardian.
  19. ^ "The Future of the Internet: Balkanization and Borders".
  20. ^ "Is the Balkanization of the Internet Inevitable?"
  21. ^ "Pakistan's Blocking Binge: First Facebook, Now YouTube; Others Inaccessible" Wired, 2010-05-20
  22. ^ "Banned: Facebook, YouTube, Wikipedia… Google?" Express Tribune, Pakistan, 2010-05-20
  23. ^ "Church of Scientology recommends Internet censorship" CIO, 2009-09-08
  24. ^ Electronic Communities: Global Village or Cyberbalkans?, March 1997 paper
  25. ^ Van Alstyne, Marshall. "Could the Internet Balkanize Science?".
  26. ^ "BBC Two - The Virtual Revolution, Enemy of the State?". BBC.
  27. ^ Hosanagar, Kartik; Fleder, Daniel; Lee, Dokyun; Buja, Andreas (December 2013). "Will the Global Village Fracture into Tribes: Recommender Systems and their Effects on Consumers". Management Science, Forthcoming. SSRN 1321962.
  28. ^ Gentzkow, Matthew; Shapiro, Jesse M. (2010-04-13). "Ideological Segregation Online and Offline". Rochester, NY: Social Science Research Network. SSRN 1588920.