Asymmetric cryptography and public key cryptography are not the same thing?
In this article I would like to share my thoughts on cryptographic terminology. Of course, the answer to the question that is in the heading (be it positive or not) will not affect the performance and security of the corresponding cryptoalgorithms, but here my goal is to understand only their classification.
Many textbooks, reference books, and Internet resources state that “asymmetric cryptography” and “public key cryptography” are synonymous, as well as “symmetric cryptography” and “secret key cryptography”. But in the case of symmetric cryptography, there are no issues, at least with me. There is both a secret key and symmetry, which is expressed in the fact that both interacting parties have the same key.
In the case of asymmetric cryptography, the situation is different. Take, for example, algorithms such as Shamir's cipher [SH] or mental poker [MP]. They are undoubtedly asymmetric, but to call them a public key cipher the language does not rotate, since there are no public keys in them at all (except for the parameters common to all subscribers, such as the module and the generator of the group).
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Moreover, asymmetric systems are often said to be such systems, where one of the keys is transmitted over an unprotected channel [AC]. In my opinion, this is precisely the definition of asymmetric systems, where asymmetry is the presence of different, rather than the same (as in symmetric cryptography) keys. In the Shamir cipher and mental poker, the keys are not transmitted over an unprotected channel; therefore, they are asymmetric systems, but not public key systems.
So maybe public-key cryptography is only a subset of asymmetric cryptography, but not all of it itself?
Literature
[] Shamir Code
[MP] Mental Poker
[AS] public key cryptosystem
Many textbooks, reference books, and Internet resources state that “asymmetric cryptography” and “public key cryptography” are synonymous, as well as “symmetric cryptography” and “secret key cryptography”. But in the case of symmetric cryptography, there are no issues, at least with me. There is both a secret key and symmetry, which is expressed in the fact that both interacting parties have the same key.
In the case of asymmetric cryptography, the situation is different. Take, for example, algorithms such as Shamir's cipher [SH] or mental poker [MP]. They are undoubtedly asymmetric, but to call them a public key cipher the language does not rotate, since there are no public keys in them at all (except for the parameters common to all subscribers, such as the module and the generator of the group).
')
Moreover, asymmetric systems are often said to be such systems, where one of the keys is transmitted over an unprotected channel [AC]. In my opinion, this is precisely the definition of asymmetric systems, where asymmetry is the presence of different, rather than the same (as in symmetric cryptography) keys. In the Shamir cipher and mental poker, the keys are not transmitted over an unprotected channel; therefore, they are asymmetric systems, but not public key systems.
So maybe public-key cryptography is only a subset of asymmetric cryptography, but not all of it itself?
Literature
[] Shamir Code
[MP] Mental Poker
[AS] public key cryptosystem
Source: https://habr.com/ru/post/335216/
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