(copying from GitHub per jonasschnelli's request) I can understand the desire to keep all reference strings to the nice 14-character version by keeping the data payload to 40 bits, but it seems to place artificial limitations on the format (year 2048 & 8191 transactions). I also understand that this might be addressed with Version 1 encoding. But current blocks are not that far from having 8191 transactions.
You could go with a variable-length encoding similar to Bitcoin's variable ints and gain the benefit of having a format that will work for very large blocks and the very far future. Also, the Bech32 reference libraries allow encoding from byte arrays into the base-5 arrays native to Bech32. It seems like bit-packing to these 40 bits might be overkill. As an alternative you could have one bit-packed byte to start: # First two bits are the protocol version, supporting values 0-3 V = ((protocol version) & 0x03) << 6 # Next two bits are magic for the blockchain # 0x00 = Bitcoin # 0x01 = Testnet3 # 0x02 = Byte1 is another coin's magic code (gives 256 options) # 0x03 = Byte1-2 is treated as the coin magic code (gives 65280 more options) M = (magic & 0x03) << 4 # Next two bits are the byte length of the block reference B = ((byte length of block reference) & 0x03) << 2 # Final two bits are the byte length of the transaction index T = ((byte length of transaction index) & 0x03) # Assemble into the first byte Byte0 = V | M | B | T This gives you up to 3 bytes for each block and transaction reference, which is 16.7 M blocks, or year 2336, and 16.7 M transaction slots. Data part: [Byte0][optional magic bytes 1-2][block reference bytes][tx reference bytes] So the shortest data part would have 3 bytes in it, with the reference version 0 genesis coinbase transaction having data part 0x050000. I know this is a departure from your vision, but it would be much more flexible for the long term. Clark _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
