Publishing

Publishing is the act of broadcasting a vendor's data to the Bitcoin blockchain. Once a vendor's data has been published, anyone can retrieve his/her data by supplying the xpubkey.

At a high level, the vendor data is compressed into a msgpack object, signed, and split into 37-byte chunks called "manifests". Each manifest is given a 3-byte header for a total of 40-bytes.

The following is pseudocode to help understand the publishing process.

//pack the vendor data using the msgpack encoding scheme
vendorDataMsg = msgpack.encode(vendorData)

//sign the vendor data with the vendor's address
signature = sign.(vendorDataMsg,vendor.address)

//compute the number of transactions a broadcast will take
transactionsRequired = ((1+vendorData)/37).roundUp()

//add everything together into a single byte array
manifest = [transactionsRequired] + signature + vendorDataMsg 

//split the bytes into chunks of 37
manifestChunks = manifest.splitIntoChunksOfByteSize(37)

//create an OP_RETURN transaction for each chunk and broadcast it to the network
manifestChunks.each(function(vendorDataMsgChunk){
    sendrawtransaction('OP_RETURN',header+vendorDataMsgChunk,vendor.address)
})

Vendor Data

All fields are to be decoded using UTF-8. Only the product image url is optional.

• Name (n)
• Currency (c)
• Pgp Key Data (k)
• Info (i)
• Array of Products (p)
  • Name (n)
  • Price (p)
  • Image URL (i) (optional)