Bitcoins

Free Coins

• DailyBitCoinsDifferent amount of free coins once per 24 hours.
• Bitcoint FaucetOne time 0.005 bitcoins per google mail account.
• Bitcoin Street FaucetFree 0.01 bitcoins per mobile phone number.

Clients

• Official Client

Pools for Mining

• bitcash.cz
• Bitocin.cz

Protocol

• Used Hashes: SHA-256 , RIPEMD-160
• Merkle Trees:
  hash(a) = sha256(sha256(a))
  hash(a) hash(b) hash(c)
  hash(hash(a)+hash(b)) hash(hash(c)+hash(c))
  hash(hash(hash(a)+hash(b))+hash(hash(c)+hash(c)))
  
• Signatures: "Elliptic Curve Digital Signature Algorithm" (ECDSA) (Used: secp256k1 curve)
  y² = x³ + a*x + b
  secp256k1: Section(2.7.1) Strength(128) Size(256) RSA/DSA(3072) Koblitz
  p = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F = 2^256-2^32-2^9-2^8-2^7-2^6-2^4-1
  a = 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
  b = 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000007
  G = 02 79BE667E F9DCBBAC 55A06295 CE870B07 029BFCDB 2DCE28D9 59F2815B 16F81798 (compressed Form)
  G = 04 79BE667E F9DCBBAC 55A06295 CE870B07 029BFCDB 2DCE28D9 59F2815B 16F81798 483ADA77 26A3C465 5DA4FBFC 0E1108A8 FD17B448 A6855419 9C47D08F FB10D4B8 (uncompressed)
  n = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE BAAEDCE6 AF48A03B BFD25E8C D0364141
  h = 01
  http://public.fh-wolfenbuettel.de/~gerndt/ecc-speidel.pdf
  
• Public keys are given as 04 "x" "y" where x and y are 32byte big-endian integers representing the coordinates of a point on the curve.
  Signatures use DER encoding to pack the r and s components into a single byte stream.
• Transaction: input(s) , input_signature(s) , recipient_address(s)
• IF input >recipient than difference is fee for first who validates
• Coinbase Transaction: no input
• Addresses
  A bitcoin address is in fact the hash of a ECDSA public key, computed this way:
  Version = 1 byte of 0 (zero); on the test network, this is 1 byte of 111
  Key hash = Version concatenated with RIPEMD-160(SHA-256(public key))
  Checksum = 1st 4 bytes of SHA-256(SHA-256(Key hash))
  Bitcoin Address = Base58Encode(Key hash concatenated with Checksum)
  The Base58 encoding used is home made, and has some differences. Especially, leading zeroes are kept as single zeroes when conversion happens.