The easiest explanation I can think of for rebroadcasting is:
#1 ShakinHandz wants to sell socks on a market and shouts "ShakinHandz selling socks for 0.01 BTC each" once.
#2 Market network all pick up the message and shout it again once for each node of the network. Thus all participants quickly know the message (within seconds).
#3 Some time passes and market participants forgot about the message. Other messages come in constantly.
#4 I (or anyone else with a full node or using the above sites) can pick up the old message and shout it again, causing a new wave of market network shout outs.
#4.1 If I would modify the message (malleability aside for a second) to say "ShakinHandz selling rocks for 0.01 BTC each" the network would detect it as invalid and possible exclude me from the market if I do it too often.
#4.2 If I would not modify the message (it stays exactly the same), but modify the signature slightly (malleability attack) while keeping it valid, the network would confirm the message under a different TX ID. This can be a problem for follow up message (somewhere here the metaphor horribly breaks). Currently nodes do not allow for this modification so its very difficult and only works on old nodes.
I hope it helps even though the metaphor was only good for the rebroadacasting itself, not the possibly modified TX.
#1 ShakinHandz wants to sell socks on a market and shouts "ShakinHandz selling socks for 0.01 BTC each" once.
#2 Market network all pick up the message and shout it again once for each node of the network. Thus all participants quickly know the message (within seconds).
#3 Some time passes and market participants forgot about the message. Other messages come in constantly.
#4 I (or anyone else with a full node or using the above sites) can pick up the old message and shout it again, causing a new wave of market network shout outs.
#4.1 If I would modify the message (malleability aside for a second) to say "ShakinHandz selling rocks for 0.01 BTC each" the network would detect it as invalid and possible exclude me from the market if I do it too often.
#4.2 If I would not modify the message (it stays exactly the same), but modify the signature slightly (malleability attack) while keeping it valid, the network would confirm the message under a different TX ID. This can be a problem for follow up message (somewhere here the metaphor horribly breaks). Currently nodes do not allow for this modification so its very difficult and only works on old nodes.
I hope it helps even though the metaphor was only good for the rebroadacasting itself, not the possibly modified TX.
It definitely does help, because I was trying to wrap my head around where malleability comes into play, and the different manipulations that might take place. I appreciate the explanation
