Error detection and correction

Channel (broadcasting)

Erasure

Algorithm

Online codes

Erasure code

Block code

Programming language

Linear code

Levenshtein distance

Synchronization (alternating current)

Computer science

Theoretical computer science

Decoding methods

Tornado code

Telecommunications

IEEE Transactions on Information Theory

Already in the 1960s, Levenshtein and others studied error-correcting codes that protect against synchronization errors, such as symbol insertions and deletions. However, despite significant efforts, progress on designing such codes has been lagging until recently, particularly compared to the detailed understanding of error-correcting codes for symbol substitution or erasure errors. This paper surveys the recent progress in designing efficient error-correcting codes over finite alphabets that can correct a constant fraction of worst-case insertions and deletions. Most state-of-the-art results for such codes rely on synchronization strings, simple yet powerful pseudo-random objects that have proven to be very effective solutions for coping with synchronization errors in various settings. This survey also includes an overview of what is known about synchronization strings and discusses communication settings related to error-correcting codes in which synchronization strings have been applied.

Synchronization Strings and Codes for Insertions and Deletions—A Survey