On Bitcoin wiki several opcodes are listed as "disabled".

My question is simple: which Bitcoin improvement proposal proposed to disable them, and when they have effectively been disabled in the past?

I'm particularly interested in the OP_MOD arithmetic opcode.

1 Answer 1


It appears many unused opcodes were disabled in 2010 for security reasons (at least OP_CAT) or as a security precaution (many others).

Pseudonymous commented that the first BIPs didn't start until 2011 - a year later.

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