The first encryption report released by the European Union's internal security innovation center pointed out that in addition to technologies such as Mimblewimble, zero-knowledge proofs, token mixers, and privacy coins such as Monero and Zcash, "Layer2 solutions such as the Lightning Network may also be abused by criminals." The report states that the "two-party multi-signature payment channel of the Lightning Network will not broadcast all transactions to the blockchain, but only broadcast the opening and closing of the channel," and adds that it and other Layer2 solutions may cause "problems for law enforcement investigations."