olemus
algoritm või algoritmipaar
andmete krüpteerimiseks ja dekrüpteerimiseks

Wiktionary:
5. (cryptography) a cryptographic system using an algorithm that converts letters or sequences of bits into ciphertext
a public-key cipher

ISO 11568, 13492:
avateksti ja krüptogrammi vaheliste
parameetriga (võtmega) operatsioonide paar;
krüpteerimine teisendab andmed arusaamatuiks,
st teisendab avateksti krüptogrammiks,
dekrüpteerimine taastab algsed andmed
= pair of operations that effect transformations between plaintext and ciphertext under the control of a parameter called a key
Note. The encipherment operation transforms data (plaintext) into an unintelligible form (ciphertext). The decipherment operation restores the original text.

ISO/IEC 18033, 29150:
andmete konfidentsiaalsuse kaitseks kasutatav
krüptograafiline meetod, mis
koosneb kolmest osaprotsessist
- krüpteerimisalgoritmist,
- dekrüpteerimisalgoritmist,
- võtmete genereerimise meetodist
= cryptographic technique used to protect the confidentiality of data, and which consists of three component processes: an encryption algorithm, a decryption algorithm, and a method for generating keys

ISO 17090 jm:
andmete teisenduse meetod nende infosisu peitmiseks,
nende avastamatu muutmise vältimiseks ja/või
nende lubamatu kasutamise vältimiseks
= method for the transformation of data in order to hide its information content, prevent its undetected modification, and/or prevent its unauthorized use

ülevaateid
https://www.khanacademy.org/computing/computer-science/cryptography/ciphers/a/ciphers-vs-codes

https://en.wikipedia.org/wiki/Cipher

https://www.thalesgroup.com/en/markets/digital-identity-and-security/magazine/brief-history-encryption

https://www.keyfactor.com/resources/types-of-encryption-algorithmns/

https://en.wikipedia.org/wiki/History_of_cryptography

https://tools.ietf.org/id/draft-irtf-cfrg-cipher-catalog-01.html

näiteid
http://practicalcryptography.com/ciphers/classical-era/

http://www.cryptogram.org/resource-area/cipher-types/

vt ka
- asendusšiffer
- asümmeetriline šiffer
- Feisteli šiffer
- hübriidšiffer
- identiteetšiffer
- jadašiffer
- liitšiffer
- permutatsioonšiffer
- plokkšiffer
- sümmeetriline šiffer
- transpositsioonšiffer