Schutzspeichers

Schutzspeichers, in computing often rendered as protected memory in English, describes a set of hardware and software mechanisms that isolate memory regions used by different programs and by the operating system. The goal is to prevent a program from reading or writing memory belonging to another program or to the kernel, thereby protecting data integrity and system stability.

The primary hardware support is a memory management unit (MMU) that translates virtual addresses to physical addresses and enforces access rights through structures such as page tables and translation lookaside buffers (TLBs). In older or simpler systems, base and limit registers or segmentation provide similar isolation. Modern systems also employ protection keys, privilege levels, and hardware features that enforce supervisor mode for sensitive operations.

Software plays a key role: the operating system sets up memory regions with specific permissions, handles page faults when a page is not present or access is illegal, and enforces process isolation so that one process cannot freely alter another's state.

Historically, Schutzspeicher emerged with virtual memory and multi-programming in the 1960s and has since become a standard aspect of all contemporary general-purpose operating systems, including Linux, Windows, macOS, and mobile platforms. The term is common in German technical literature, where it is used to describe the broader concept of memory protection.

Limitations exist: Schutzspeicher reduces but does not eliminate risk. Bugs such as buffer overflows, use-after-free errors, or misconfigured permissions can still enable violations. Secure coding, defensive programming, and additional sandboxing complement the protection provided by the hardware and the OS.