Christian Decker is a Bitcoin and Lightning researcher and developer. Lightning is a network for payments through payment channels. He has worked on data propagation research, eltoo, BIP 118 and Greenlight. His contributions are easiest to understand through the problems they address: different information across the network, outdated balance agreements and the work involved in operating a node.
Looking for Decker’s work brings you to the account cdecker and the name Snyke. His public profile also listed Blockstream when checked in October 2026. This helps connect an author with code and proposals, but a short profile alone does not establish his current job title. In an open network, a proposal stands on the problem it solves and how it withstands review. An author’s name or employer gives no authority to change everyone else’s rules. [1]
A new block travels through the network in stages: one computer passes it to others, and transmission takes time. Christian Decker and Roger Wattenhofer measured this in a 2013 study. They examined transaction and block propagation and how delays relate to temporary chain splits, when different parts of the network work with different newly found blocks. These historical measurements illuminate practical network behavior; they do not describe Bitcoin’s current speed. Software and transmission methods have changed since then. [2]
In a payment channel, participants repeatedly agree on their shares of funds committed together. What if someone closes it using an older agreement that favors them? The eltoo proposal by Decker, Rusty Russell and Olaoluwa Osuntokun lets a newer state override an older one before final settlement. Think of replacing an outdated account statement with the latest agreement. This is a proposed mechanism, not automatically a feature of every Lightning channel in use today. [3]
Being able to correct an old state is not enough. In eltoo, a corrective transaction must confirm before the old state can settle. OP_CSV provides the response window: it permits a particular spend only after a specified waiting period following confirmation of the relevant output. The user or an appointed service must therefore monitor the chain. The proposal changes how old states are handled, but does not make unlimited offline periods safe. [3]
Applying a newer agreement to different earlier states requires suitable signature rules. BIP 118, by Decker and Anthony Towns, proposes SIGHASH_ANYPREVOUT. When checked in October 2026, the document was marked Draft and described a consensus change through a soft fork: a change to the rules nodes use to validate Bitcoin. Publishing a document or gaining developers’ support is not evidence of network activation. Proposal, implementation and adoption are separate steps. [4]
A signature normally commits to the specific previous transaction output being spent: an amount with spending conditions. BIP 118 relaxes that link in a chosen mode, letting a signed transaction bind to another compatible output. This helps replace outdated channel states; it does not let anyone spend arbitrary funds belonging to others. The wider scope for signature replay, meaning reusing a signature, requires careful design. Commitments to the amount and spending conditions also matter, depending on the chosen mode. [4]
Running a Lightning node takes ongoing work. Blockstream announced Greenlight’s public launch on 12 October 2023, naming Decker as project lead. The service separates tasks: users hold their private keys while a provider runs node infrastructure. A private key authorizes spending, so holding it is different from operating a server. This arrangement guarantees neither uninterrupted service availability nor unchanged commercial terms. Those need to be assessed separately. [5]
Core Lightning is software for running a Lightning node. Plugins extend it to suit an operator’s needs, and reckless helps install and activate them. That is a different kind of change from proposing new Bitcoin signature rules. Installing a plugin does not itself add BIP 118 to the rules of the entire network. Decker’s work connects research, protocol proposals and practical tools, but each follows its own path from an idea to actual use. [6]
For the clearest picture, read this entry together with Elizabeth Stark, Andreas Antonopoulos, Lightning Network. The reverse links also lead from Elizabeth Stark, Andreas Antonopoulos.