Blockchain and ISO/OSI I've heard blockchain is built on top of the ISO/OSI stack. Does it means blockchain belongs to the layer 7 (Application layer) of the Osi architecture?
Bitcoin uses TCP which would put it at layer 7 of that description, but there's nothing particular that requires it. The transport layer for data is orthogonal to the system, it could alternatively use raw frames, carrier pigeons, or have the packets inked onto the heads of slaves. Systems exist which allow for data to be transfered through a TV satellite relay for example, which skips the networking layers entirely.