Utxo commitments are hashes put into blocks that summarize the current unspent transaction output set.
2015-05-04 - Locally verifiable unspent transaction output commitments
2013-12-20 - BIP proposal: Authenticated prefix trees
2013-10-19 - Spending Outputs with Merkle Proofs
2011-06-24 - Merkle tree of open transactions for lite mode
2014-03-28 - miner commitments with compact proofs
2015-05-10 - Extending transactions to include UTXO info
2014-03-03 - Namecoin that sucks less
2014-11-12 - Auxiliary Header Format
2012-06-17 - Trust-free lite nodes
2012-05-07 - Using P2SH Hashes as the 'key' instead of txos
2012-10-08 - redblackmerkle - self balancing merkle trees
2014-07-28 - Unspent Transaction Output Based Certificates
2012-10-10 - Pruning the Utxo Set
2013-05-13 - Fundraising for Ultimate Blockchain Compression
2014-10-05 - alt ideas
2015-05-21 - Helix Blockchains
2012-07-06 - Ultraprune - using utxo set instead of txn set
2015-08-30 - Demurrage based utxo pruning
2015-07-21 - Deleteting Abandoned UTXO
2013-02-21 - Allowing Blocks to be Prepared ahead of time
2014-11-03 - Use block size hardfork to also implement utxo commitments
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