in this paper, we propose a new method for the numerical solution of two-dimensional linear and nonlinear volterra integral equations of the first and second kinds, which avoids from using starting values. an existence and uniqueness theorem is proved and convergence isverified by using an appropriate variety of the gronwall inequality. application of the method is demonstrated for solving the ...

A method for deriving a public key encryption system from any ‘conventional’ (secret key) block cipher is described. The method is related to, but improves upon, Merkle’s ’puzzle system’.

In this paper, we present One-key CBC MAC (OMAC) and prove its security for arbitrary length messages. OMAC takes only one key, K (k bits) of a block cipher E. Previously, XCBC requires three keys, (k + 2n) bits in total, and TMAC requires two keys, (k + n) bits in total, where n denotes the block length of E. The saving of the key length makes the security proof of OMAC substantially harder th...

We demonstrate that the existence of distinguishing attacks against stream ciphers is unrelated to their security in practical use, and in particular that the amount of data required to perform a distinguishing attack is unrelated to the key length of the cipher. The implication for the NESSIE Project is that no submitted symmetric cipher would be accepted under the unpublished rules for distin...

The block cipher CRYPTON is a candidate proposal for the AES standard. In this report we describe a class of 232 weak keys. This is mainly a consequence of the use of linear operations in the key schedule. These weak keys especially have consequences for the use of CRYPTON in certain hash function constructions.