When a transaction is broadcasted to the network, the transaction string contains the little-endian of SHA256(SHA256(X)) where X is the transaction string of input transaction.
Now, since SHA is irreversible, miners will not be able to get the full transaction string (X). So, how do miners verify the authencity of the input? How do they know that the mentioned input transaction actually had 'n' outputs? I am looking to understand the alogirthm behind this.