Kontrollkod

Kontrollkod is a Swedish term that translates to "control code" or "verification code." In Swedish usage it can refer to several related concepts meant to ensure correctness, integrity, or authorized access. The exact meaning depends on context, and it is not a single standardized term.

In computing and telecommunications, kontrollkod frequently describes control codes—non-printable characters that direct a device or software to perform an operation rather than to display a symbol. Examples include line feed or escape, and they are part of character sets such as ASCII. In software development, it can also denote flags or instructions that alter program flow.

In data validation and identification, kontrollkod is often used as a check digit or verification code that helps detect input errors in numbers such as account numbers, product codes, or serial numbers. The check digit is computed from other digits using algorithms such as the Luhn algorithm or ISO/IEC 7064, and is used to validate data entry or transmission.

In security contexts, a kontrollkod can refer to a temporary or one-time code used for authentication or transaction authorization, for example codes delivered by SMS or generated by an authenticator app. These codes are typically time- or event-based and are separate from passwords.

Because of its broad usage, the term kontrollkod should be understood from domain context. It is often distinguished from related terms such as kontrollsiffra (check digit) and lösenord (password).