A [[content-addressable scheme]] ([[CAS]]) is a system that allows data to be accessed and retrieved by its content, rather than by its location. This is in contrast to traditional systems, which store data in a fixed location and require the user to know the location of the data in order to access it. CAS systems are often used in distributed systems, where the data is stored on multiple computers. In a CAS system, each piece of data is assigned a unique identifier, called a content identifier (CID). The CID is a hash of the data itself, so it is unique for each piece of data. To access a piece of data in a CAS system, the user simply needs to know the CID of the data. The system can then use the CID to locate the data, regardless of where it is stored. CAS systems offer several advantages over traditional systems. First, they are more efficient, as they do not require the user to know the location of the data. Second, they are more scalable, as they can be easily extended to store more data. Third, they are more secure, as they can prevent unauthorized access to data. CAS systems are used in a variety of applications, including: - Distributed file systems - Content delivery networks - Peer-to-peer networks - Blockchain - Cryptography Here are some of the examples of CAS systems: - [[Content-addressable memory]] (CAM) - [[Distributed Hash Table]] ([[DHT]]) - Blockchain - Merkle tree CAS systems are a promising technology with a wide range of applications. As the need for distributed and scalable systems grows, CAS systems are likely to become more widely used. # References ```dataview Table title as Title, authors as Authors where contains(subject, "Content Addressable Scheme") ```