S-63 is an International Hydrographic Organization (IHO) standard for

encrypting In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can deci ...

, securing and compressing

electronic navigational chart An electronic navigational chart or ENC is an official database created by a national hydrographic office for use with an Electronic Chart Display and Information System (ECDIS). An electronic chart must conform to standards stated in the Interna ...

(ENC) data. The Data Protection Scheme was prepared by the IHO Data Protection Scheme Advisory Group, and was based on the protection scheme developed and operated by Primar as part of providing their protected ENC service. ECC (Electronic Chart Centre) and

United Kingdom Hydrographic Office The United Kingdom Hydrographic Office (UKHO) is the UK's agency for providing hydrographic and marine geospatial data to mariners and maritime organisations across the world. The UKHO is a trading fund of the Ministry of Defence (MoD) and is ...

were the original contributing organizations. The UKHO has since left this arrangement and Primar is now operated exclusively by ECC. The standard was adopted as the official IHO standard by the IHO member states in December 2002. The S-63 standard secures data by encrypting the basic transfer database using the

Blowfish Tetraodontidae is a family of primarily marine and estuarine fish of the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowies, bubblefish, globefish, swellfis ...

algorithm,

SHA-1 In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecima ...

hashing Hash, hashes, hash mark, or hashing may refer to: Substances * Hash (food), a coarse mixture of ingredients * Hash, a nickname for hashish, a cannabis product Hash mark *Hash mark (sports), a marking on hockey rinks and gridiron football field ...

the data based on a random key and adding a

CRC32 A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on t ...

check. The standard also defines the systems to develop permit files that are delivered to end-users of ENC data enabling them to decrypt the data and use it for navigation. It also defines the use of DSA format signatures to authenticate the data originator, however because of poor implementation of the standard by

ECDIS An Electronic Chart Display and Information System (ECDIS) is a geographic information system used for nautical navigation that complies with International Maritime Organization (IMO) regulations as an alternative to paper nautical charts. IMO re ...

hardware manufacturers, virtually all signing is performed centrally by the

IHO The International Hydrographic Organization (IHO) is an intergovernmental organisation representing hydrography. , the IHO comprised 98 Member States. A principal aim of the IHO is to ensure that the world's seas, oceans and navigable waters a ...

which acts as the scheme administrator. Exceptions to this are a few smaller resellers such as AUSRenc operated by AHS. Compression is achieved by applying the standard

ZIP (file format) ZIP is an archive file format that supports lossless data compression. A ZIP file may contain one or more files or directories that may have been compressed. The ZIP file format permits a number of compression algorithms, though DEFLATE is the ...

algorithm to the base and update ENC files, before encryption. The other files are not compressed.

References

{{reflist Digital rights management Electronic navigation