Bitcpoin - Security that the output was not altered

[ferjamartini]

Can someone remove the following doubt?

If the output of a transaction is not digitally signed, how can it be prevented that someone, in the network, intercepts the message and changes the direction of the output before a miner accepts it?

thanks.

[ranochigo]

The signature encompasses the output script and the amount too. Essentially, the signature will contain all of the transaction data (except the scriptsig and the signature itself), the output script is not excluded. The signature basically proves the ability of the transaction to spend the UTXO as well as the transaction outputs. If the transaction output is modified, the signature will not validate and thus the transaction would become invalid.