SHA256 doesn't generate characters, it generates bytes that are usually rendered in hex form, which gives you the "first character".
There isn't a known way to calculate just the first bytes of a SHA256 hash faster. Each step in SHA256 depends on the value of the previous step, so you have to calculate the whole thing through. SHA256 is meant for cryptography and would be considered vulnerable to attacks if a shortcut were known.
There isn't a known way to calculate just the first bytes of a SHA256 hash faster. Each step in SHA256 depends on the value of the previous step, so you have to calculate the whole thing through. SHA256 is meant for cryptography and would be considered vulnerable to attacks if a shortcut were known.