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What does the public key address start at? and end? is that available? i was trying to see howmany public keys are available, and it would be cool to know at what number it starts and ends. the complete publickey with 04 bit on it

Rob
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Bitcoin public keys are simply points on the elliptic curve secp256k1. Each point has an x and y value, and an (uncompressed) public key is encoded with the 0x04 to show that it is an uncompressed public key as opposed to a compressed or other, and then followed by the x and y coordinates, each 32 bytes long. The 0x04 is just a prefix, the key itself is the point on the curve.

There are 2 interpretations of first and last keys that I can see. Either you mean the 'first' key is the one corresponding to a private key of 0x01, or the key with the smallest x and y values. secp256k1 is the curve y2 = x3 + 7, so any x and y values that satisfy this equation (modulo the prime p = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F [ref]) is a valid point on the curve and thus public key. So x=0, y=1 would not be a valid point, because it doesn't satisfy that equation.

meshcollider
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i was trying to see howmany public keys are available

~ 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 may be a couple less :)

the complete publickey with 04 bit on it

do not mix the public key and standatized written form of it

amaclin
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  • I think you should include where that number came from, perhaps explaining what a public key actually is, and what the 0x04 means – meshcollider Aug 21 '17 at 11:03
  • Thats what im trying to figure out, what role the 04 comes into play – Rob Aug 21 '17 at 14:11
  • So would it be something like this for the X & Y points? What would the last public key look like? 04FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 ? – Rob Aug 21 '17 at 14:13
  • 'last' private key is FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364140 'last' public key is 0479BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798B7C52588D95C3B9AA25B0403F1EEF75702E84BB7597AABE663B82F6F04EF2777 – amaclin Aug 21 '17 at 20:04
  • I know that that public key goes with that last private key, but numberwise, the public keys go higher then that, im trying to figure out what the #1 public would be be in hex format, something like this 0400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 this gives me a good address of 1JHkucsiQt3WizTfd2r1b9sGeT6cUBXPii but is it valid on the blockchain? – Rob Aug 21 '17 at 21:49
  • Please update the question and answer with the new information rather than using the comments section :) – meshcollider Aug 22 '17 at 06:18