Auroracoin is a decentralised, peer-to-peer, and secure cryptocurrency released as an alternative to the Icelandic Króna to bypass governmental restrictions associated with the national fiat currency. It was launched with the aim of becoming the ‘official’ cryptocurrency of Iceland. AUR was a pioneer in the area of country-specific cryptocurrencies. AUR was launched on the 25th of January, 2014, by an anonymous developer who went by the pseudonym of Baldur Friggjar Óðinsson. It was originally based on Litecoin, using the Scrypt algorithm with a Proof of Work mechanism, but was later updated to use a multi-algorithm architecture in 2016, forked from DigiByte. Auroracoin uses the PoW consensus mechanism, which utilises device hashing power to solve a complex mathematical problem in order to authenticate a transaction proposed to be stored in the blockchain. The difficulty of solving the problem ensures that authenticating forged transactions is very difficult unless the attacker owns an impractically large chunk of the network’s total hashing power. AUR is one of the only cryptocurrencies to use a combination of five different hashing algorithms, namely Grøstl, Qubit, scrypt, SHA-256, and Skein. While initially very popular, Auroracoin has seen little to no activity for a while, with poor marketing, and frequent dev team changes. Reasons for little growth have been various, from slow adoption in Iceland, to developers leaving and joining the project midway. However, it is expected to not go lower than the recent low, and might see a rise as AUR plans to launch a more aggressive marketing campaign in Iceland to promote the coin among the masses. Unlike most other altcoins, Auroracoin has made extensive changes to the original codebase. It has introduced security measures such as Automatic checkpointing, and protecting against known flaws present in the BTC blockchain, such as 51% block replacement attacks.
BlackCoin started of as a Proof of Work coin but has evolved to a unique version of Proof of Stake. Wallet users can unlock wallet for staking only. BlackCoin features the following specifications: - Extremely secure: Among first with fix on SSL heartbeat, Transaction malleability, BIP66 - The probability to sign a block and the block reward does not depend on coinage (anymore). - Recommended confirmations: 10, maturity: 500 - Minimum transaction fee: 0.0001 BLK - Defined block time target: 64 seconds - Max reorganization depth: 500 blocks - Inflation: about 0.95%. - PoS block reward: 1.5 BLK + fees - The accumulated reward is proportional to the total balance and the time of staking. 24/7 staking at current network weight leads to an expected reward ratio (interest rate) of about 5%. - BlackCoin rewards users who supports the blockchain through continuous staking.