Crypto-currencies

Crypto-currencies are digital online currencies that exhibit that use cryptographic algorithms to control the supply to create "virtual scarcity" and to overcome the counterfeiting and double spending problems. The first was Bitcoin, and then many more began to arise with their own unique properties, strengths and weaknesses such as Litecoin and Namecoin. Crypto-trading is now becoming very popular which is the idea of making money by transferring value between the various crypto-currencies as their value changes with respect to one-another. Usually Bitcoin is used as the base currency since all exchanges that offer multiple crypto-currencies allow them all to be bought or sold with Bitcoins.

Exchanges offering multiple crypto-currencies

• BTC-E
• CoinMKT
• Crypto Trade
• Cryptsy
• Kraken
• Bter

Sites with charts for multiple crypto-currencies

• Crypto-Currency Market Capitalisation - graphs of the market cap of over forty cryptos
• BitcoinWisdom - awesome chart service covering many currencies and exchanges
• Crypto Trade - this exchange has historical charts of about ten cryptos
• Bter - this exchange has historical charts of many cryptos
• CoinMKT - this exchange has historical charts of many cryptos (need to be logged in)
• TheWorldWantsBitcoin - good stats on use by country and top cryptos
• Crypto Coin Charts - good info on vaious coins and exchanges and their trading volume

Proof of retrievability

This is an awesome idea! Permacoin solves two major problems with bitcoin in one elegant solution. The problem of the huge waste of resource that mining occupies, and the problem that the bitcoin network has no mechanism for large-scale data storage.

Permacoin flips the mining paradigm on its orthogonal axis by saying that instead of time=money (i.e. processing power to mine coins with proof of work), they make space=money! "Miners" offer space to the network in a proof of retrievability system resulting in a usable distributed storage system instead of teraflops of unusable processing :-)

This effort is backed by Microsoft so may end up with some closed-source soul-selling strings attached, but the idea of proof-of-retrievability is sure to be an up and coming concept in the crypto future!

See also

• Bitcoin
• Ethereum
• QuarkCoin: Noble Intentions, Wrong Approach
• Profitability of the cryptocoins BTC LTC FTC PPC NMC IXC DVC FRC CNC BTE MNC BQC YAC
• Good article on PeerCoin
• Coin Pursuit - good site offering a broad range of info for crypto traders
• 10 signs that MaxCoin was the largest altcoin launch in history
• Map of Coins
• List of exchanges on dotbit.org
• Development of an Open and Flexible Payment System - good doc on cryptocurrency written by Gary Howland in 1996