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3 Conclusions

Asymmetric cryptosystem based on algebraic block codes have been proposed about 40 years ago

and then were perceived by most researchers as a kind of exotic and not very applicable in the area
of cryptography. For a long time obvious disadvantages (large volumes of key data and relative

transmission rate decrease) restrained their further development and practical use. Only in recent
years, when it became clear that many of the existing, standardized and widely used cryptographic

algorithms in practice may prove defenseless against the attacks of the quantum cryptanalysis, code

cryptographic received well-deserved attention from researchers. Decoding random code - an
extremely difficult computational problem and brute force search at searching for its decision -

probably the best of the currently known solution. Quantum algorithms accelerate this process, which
reduces the time required of the cryptanalysis, but this reduction is not critical (approximately

equivalent length decreases key twice). In fact, it should be acknowledged that the code
cryptosystems are a real alternative to modern asymmetrical cryptosystems (RSA, ECC, or other) as

part of the construction of the reliable postquantum algorithms. Given calculations in Table 1 clearly

confirm this conclusion. Furthermore, features of building code schemes allow simultaneously with
the crypto protection to realize an additional service control of the occurred errors, which is certainly

of interest to the telecommunications systems of special purpose.

For the practical use of code cryptosystems is necessary to solve (or accept with their existence)
some structural problems. First, the most obvious problem is the huge volumes of key data. These

volumes would have to significantly increase (about four times) due to the possibility of using
quantum computing systems. For example, for the considered variants (see Table 1), volumes of keys

reach the hundreds of megabits and is not yet possible to reduce them without lowering of the
resistance cryptosystem. The keys in of code schemes are the generator (generating and / or

validation) matrices of a linear code, which should look for an attacker like random set of the linear

and independent vectors. Compress or somehow reduce this set is not feasible.
The second problem - the relative low data rate - partly solved in the present manuscript. Proposed

authors’ new encryption scheme, which actually unites the known encoding methods of information
data (used in the McEliece and Niederreiter schemes). As a result, the relative speed increases, which

also increases the overall effectiveness of the cryptosystem. If you use an effective (in the sense of
remote properties) codes, the relative speed will be nearly 100%. Even for designs that are well below

the upper code boundaries is a significant (30-40%) increase in the relative data rate (see Table 2).

This improvement, according to the authors, would allow to start developing specific protocols for
cryptographic protection using of code schemes and to begin their practical implementation.

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