The recent re-emergence of transaction malleability has been responsible for a large number of Txs which are being double spent (October 2015).
/r/Bitcoin has posted some C++ code which @amaclin has taken responsibility for.
I understand that, based on this source code, the transaction malleability "exploit" is simply tweaking the DER signatures for certain Txs (ie non P2SH Txs) and rebroadcasting the Tx (disclaimer: I don't know C++ so these are educated guesses).
BIP62 deals with numerous issues, amongst these is the requirement for canonical DER signatures: I was under the impression canonical DER signatures was implemented in BIP66.
- Can someone clarify what @amaclin's code is doing?
- Why is this exploit possible if BIP66 was implemented several weeks ago?