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 de ...
, 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 Inte ...
(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.
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The S-63 standard secures data by encrypting the basic transfer database using the
Blowfish 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 hexadec ...
-
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 fiel ...
the data based on a random key and adding a
CRC32 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 hardware manufacturers, virtually all signing is performed centrally by the
IHO which acts as the scheme administrator. Exceptions to this are a few smaller resellers such as
AUSRenc operated by
AHS
AHS may refer to:
Schools
* Adelaide High School, Adelaide, Australia
* Aitkin High School, Minnesota, USA
* Agoura High School, Agoura Hills, USA
* Albemarle High School (Virginia), USA
*Alice High School, Texas, USA
*Allen High School (disamb ...
.
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 th ...
algorithm to the base and update ENC files, before encryption. The other files are not compressed.
References
{{reflist
Digital rights management
Electronic navigation