I have been looking at some unusual txouts in the block chain, e.g., the first 34 txouts of
237783998a6799264983150187a73ab6d116f2ba78d3e1f88529e95229f59d67
Bitcoin Core classifies them as "pubkey" type outputs. For example:
{
"value" : 0.00000001,
"n" : 0,
"scriptPubKey" : {
"asm" : "7d0800003b23280b343933313020383335393720303238353020313930303220373537373720363732333920303736343920353732383420393037373720323135 OP_CHECKSIG",
"hex" : "417d0800003b23280b343933313020383335393720303238353020313930303220373537373720363732333920303736343920353732383420393037373720323135ac",
"type" : "pubkey"
}
However, the (uncompressed) pubkey is usually 65 bytes of the form "04 x y". Here the leading byte is "7d".
To try to spend this txout, [a signature for*] this ill-formated "pubkey" would need to be given and I would expect the script to fail at OP_CHECKSIG. Is this correct? I can also imagine OP_CHECKSIG ignores the leading byte, but even in this case the (x,y) is not on the curve.
Does such a txout qualify as "provably unspendable"?
* Edit: added "a signature for"