Mutual Distributed Ledger (MDL, aka blockchain) technology is set to transform the way people and organisations handle identities, transactions, debts, and contracts. As a source of transparent, authoritative and immutable records, mutual distributed ledgers foster better coordination through improved trust and the faster distribution of targeted information between parties. Z/Yen’s mutual distributed ledger software suite, ChainZy, provides the basic architecture for wide variety of MDL services. It integrates the knowledge Z/Yen has accumulated in mutual distributed ledgers over two decades. Z/Yen’s first MDL was built in 1995. Since then Z/Yen has probably developed more (and more various) MDLs than any other house, perhaps 200 with about fifty major variants.

Z/Yen's software suite, ChainZy, provides the base architecture for a range of applications. Typically, Z/Yen focuses on building ledgers for communities who do not wish to have the expensive overhead of cryptocurrency 'mining', though ChainZy can handle cryptocurrency and digital money applications as well. Z/Yen has implemented ChainZy-based solutions in a number of different contexts across commerce from identity validation and insurance to clinical trials and time-stamping.

Perhaps the easiest demonstration of ChainZy is MetroGnomo, a global timestamp, archive and retrieval service, that is accessible to anyone with an email. MetroGnomo allows a user to generate proof that a given piece of stamped information existed at a certain time, without revealing the underlying piece of information. Developed initially as an experiment to create the simplest mutual distributed ledger possible, the five current versions of MetroGnomo record over 60,000 clinical interactions a day, support a sharing economy insurer and help musicians timestamp music.

ChainZy supports a variety of validation and consensus mechanisms from master nodes, to master-supervisor nodes, free-for-all, unanimity, and weighted voting mechanisms. A special ChainZy validation mechanism is 'woven broadcasting'. Woven broadcast technology employs a series of transmitters and receivers. To add to the ledger, a party sends information to a transmitter which agnostically broadcasts - that is without knowledge of those receiving the broadcast - the new ledger entry to the network of receivers. These receivers write the new entry onto their own copy of the ledger. Receiver hosts can opt to receive broadcasts, from one or more transmitters, of information from one, many or all parties submitting entries. Receiver hosts, or cooperating parties, can easily check whether their ledger is complete by checking the row and table hashes of consecutive entries.

A client can either decide to run their own receiver or to access a copy of the ledger from a party willing to share. A party running a receiver can opt to collect all the ledger entries from any of the three transmitters, or just those they can decrypt. Those holding an incomplete or sub-ledger can reconstitute the full ledger by requesting the entries other receiver hosts hold between these two entries' MetroTimes and then "stitching" them back into their own copy of the mutual distributed ledger.

"Ledgers are the infrastructure of finance. Mutual distributed ledgers are pervasive and permanent. They will transform all financial trust architectures - exchanges, insurers, banks, and information providers."

- Professor Michael Mainelli, Executive Chairman of Z/Yen (2015)