blockoriented

Blockoriented is an adjective used in computing to describe systems, interfaces, or algorithms that operate on fixed-size units called blocks. In block-oriented processing, data are divided into blocks of a predefined length and each block is treated as a discrete unit for processing, storage, or transmission. This contrasts with stream-oriented designs, which handle data as a continuous flow without explicit block boundaries.

Block-oriented techniques are common in cryptography, where block ciphers encrypt fixed-size blocks (for example 8 or 16 bytes) and require padding for the final incomplete block. Modes of operation such as ECB, CBC, and CFB define how blocks relate. Block-oriented storage and filesystems interact with data as blocks of fixed size on a device, enabling random access, caching, and efficient I/O; commonly 512-byte sectors or 4 KiB pages.

Advantages include predictable memory usage, easier parallelism, and alignment with cache lines and hardware block devices. Disadvantages include potential padding overhead, latency at block boundaries, and inefficiency for small messages or streaming workloads.

In software design, block-oriented APIs read and write data in blocks, sometimes with buffering to accumulate a full block before processing. Data compression and signal processing may also use block processing to exploit vector instructions.

Block-oriented concepts also appear in data transmission and storage protocols, where data are transmitted in fixed-size frames or blocks, allowing error detection and synchronization.

See also: block cipher, block device, block size, padding, buffering, streaming I/O.