IT Information Theory labs 1 Laba Simplest Ciphers Columnar improved method; Vigenere method; Decimation method. 2 Laba Stream Сipher $$x^{33}+x^{13}+1$$ (...and other primitive polynomials) 3 Laba Asymmetric Cryptography Rabin cryptosystem. 4 Laba Digital Signature DSA.