Sia uses Reed-Solomon erasure coding to secure and store data across multiple nodes. On Sia, data is split into 30 individual pieces, with some of these pieces acting as parity blocks. Each piece is stored on a different node across the globe. Of these 30 pieces, only 10 are required to be accessible in order for the file to be compiled for the file to be retrieved. This way, up to 20 nodes can be offline or inaccessible, and the file can still be accessed.