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Opcode number: 134
Byte representation: 0x86
Short description: Fail the script unconditionally, does not even need to be executed.

OP_XOR is a disabled opcode in the bitcoin scripting system.

Historical Context

Originally designed for Bitcoin's script, the OP_XOR opcode was intended to carry out a bitwise XOR (exclusive or) operation on the top two items on the stack. This operation would take two numbers and produce a new number wherein each bit is the result of the logical XOR between the corresponding bits in the input numbers.

However, as part of a broader effort to reduce potential vulnerabilities and to simplify bitcoin's scripting language, OP_XOR was disabled early in bitcoin's history along with several other opcodes.


Due to its disabled status, any script containing the OP_XOR opcode will cause the transaction to be invalidated, regardless of any other conditions or script context.