Platón, Sofista 256 e 5-6

5 a Novel 256 - Bit Block Cipher

Tornado is a novel 256-bit block cipher that accepts a variablelength key up to 256 bits. The proposed cipher was built on an idea which gives it a dynamic nature. This nature means that the cipher execution flow varies according to the user’s input key. The confusion and diffusion processes are performed based on 10 round functions named “Storm-functions”. A selection and reordering operations...

Mechanism of inactivation of S-adenosylhomocysteine hydrolase by (E)-5',6'-didehydro-6'-deoxy-6'-halohomoadenosines.

S-Adenosylhomocysteine (AdoHcy) hydrolase is irreversibly inactivated by (E)-5',6'-didehydro-6'-deoxy-6'-halohomoadenosines (EDDHHAs, halogen = I, Br, and Cl). The inactivation is concomitant with the reduction of the enzyme-bound NAD+ (E.NAD+) to NADH, the release of halide ion, and the formation of adenine (Ade) from the EDDHHAs. The mechanism of this inactivation involves two catalytic pathw...

(E)-2-Meth­oxy-6-[(5-methyl­isoxazol-3-yl)imino­meth­yl]phenol

In the title mol-ecule, C(12)H(12)N(2)O(3), the benzene and isoxazole rings form a dihedral angle of 5.9 (6)°. The hydr-oxy group is involved in an intra-molecular O-H⋯N hydrogen bond [O⋯N = 2.616 (5) Å], resulting in approximate planarity of the mol-ecular skeleton. In the crystal structure, mol-ecules related by translation along the c axis are stacked into columns, the shortest inter-molecul...

3 - 6 - 2009 Multi - quasiparticle States in 256 Rf

An E cient State Recovery Attack on X-FCSR-256

We describe a state recovery attack on the X-FCSR-256 stream cipher of total complexity at most 2. This complexity is achievable by requiring 2 output blocks with an amortized calculation e ort of at most 2 table lookups per output block using no more than 2 table entries of precomputational storage.