5

That would appear to be RC4, which is a well known (if not well trusted) cryptographical algorithm, original designed by Ron Rivest. The part you quoted is the Key Setup Algorithm, which is run before you actually encrypt/decrypt anything. The part which is written in an unusual (but correct) way is the last 5 lines, which does a swap of cdict[i] and cdict[...


3

VMAC was a joint work by Wei Dai and Ted Krovetz. It so happens that Wei Dai at that time was also actively working on his own cryptographic library (Crypto++), which of course also includes VMAC. You can find the test vectors here and the optimized implementation here. Two examples for VMAC-AES-128 are: Key: "abcdefghijklmnop" IV: "bcdefghi" Message: "" ...


2

Aren't they delievering by the network the same as the encypted messages? No. At least not in the plain. What doing it end-to-end encrypted? Try to search for the key agreement protocol (e. g. Diffie-Hellman ) and asymmetric encryption (e.g. RSA ). The "asymmetric" encryption allows sending encrypted and signed messages without sharing the private (...


1

$A:\mathbb{F}_2^m\rightarrow \mathbb{F}_2^m$ is the state space map induced by the primitive length $m$ LFSR. Thus it maps the zero vector of length $m$ to itself and in general the LFSR state $(a_0,a_1, \ldots,a_{m-1})$ to $(a_1,\ldots,a_m)$. $A^i$ is just $A$ iterated $i$ times (shift LFSR $i$ times). Then, the APN map $z=(z_1,\ldots,z_n)=F(x_1,x_2)$ ...


1

In a "fair trade" paper at Bitcoin workshop Financial Crypto 2016, a snark-proof was introduced to assure that a message (a Sudoku solution) could be properly decrypted.


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