Sumários

Towards signing - Hash functions

22 abril 2019, 15:30 Paulo Alexandre Carreira Mateus

Hash functions. Weak and strong collision free functions. P=NP vs existence of cryptographic hash functions. Birthday attack. Attacks to currently used cryptographic hash functions.


Towards signing - Hash functions

22 abril 2019, 15:30 Paulo Alexandre Carreira Mateus

Hash functions. Weak and strong collision free functions. P=NP vs existence of cryptographic hash functions. Birthday attack. Attacks to currently used cryptographic hash functions.


Signature Schemes

11 abril 2019, 13:00 Paulo Alexandre Carreira Mateus

Signature scheme from a cryptosystem. RSA signatures scheme. DSS and ElGamal signature scheme. Attacks to signing.


Signature Schemes

11 abril 2019, 13:00 Paulo Alexandre Carreira Mateus

Signature scheme from a cryptosystem. RSA signatures scheme. DSS and ElGamal signature scheme. Attacks to signing.


Attacks to discrete log 2

8 abril 2019, 15:30 Paulo Alexandre Carreira Mateus

Bit-security of the discrete log: 2nd lsb is in P is equivalent to the DLog problem being in P. Overview of Elliptic Curves. Computing efficiently nP with Double & Add. Discussion on trace-one curves and possible side-channel attacks on the Double & Add. Exercise related to a cryptosystem based on quadratic residues.