Quote from: danneu on January 07, 2014, 08:58:05 PM

Good stuff.

The reference Bitcoin implementation obfuscates the core simplicity of transaction validation by oddly referring to scripts as "scriptPubKey" and "scriptSig" instead of "inputScript" and "outputScript".

Realizing that "owning bitcoin" just means that you can provide a stack of instructions that evaluates to true when appended to another arbitrary instruction stack is what inspired me to hack on Bitcoin in the first place.

Some feedback:

It's worth pointing out that "true" is really just "any non-zero value" rather than a boolean literal. In other words, a script is logically valid as long as the top stack value is not 0 and as long as the evaluation isn't short-circuited by an instruction like OP_RETURN.
The significance of instructions like OP_RETURN and OP_VERIFY is that they short-circuit the evaluation. Otherwise, the script will evaluate in full and the final top stack value will determine the state of the stack. That's why you can append arbitrary data after OP_RETURN -- it's so that the data won't be evaluated.

Hey thanks, Ive inserted your comments as foodnotes in page 2 and 5. I would like to permalink to the comment as a citation but seems ont te be possible