Today I noticed a transaction that spends a bunch of 1-of-1 multisig P2WSH inputs:

For example, the first input has this script in the witness:

OP_PUSHBYTES_33 031f1c516fc9362202883b24fd92e6548776a8f1701baca38b63bbe635da8a82f7

I then wrote a script to find more of these transactions, and it turns out in the last 1000 blocks there were 3883 transactions spending 1-of-1 multisig inputs. This one spends over 30 BTC: 4d8a475e7a0433ef84baec9ec941342cb31d4194b42dedccdc4503e4acad02f8

Why would anyone use this instead of P2WPKH which is both cheaper and has a larger anonymity set?


1 Answer 1


You may be looking at transactions of an unknown entity dubbed "Crazy1o1". To my knowledge, it is still unknown who they are or why they are using 1-of-1 transactions, but they've been active for years. Notable mentions:

Update: LaurentMT suggests that Crazy1o1 is a “Crypto and Forex broker named KOT4X”


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