Abstract
In the paper we present a new cryptographic hash function called Petra-r, where ris an element of{192, 256} is the bitlength of the hash result. In designing Petra-r hash functions we formulated some goals, and one of them is especially crucial: processing an input message, the order of accessing source words should be data driven, i.e., the source words should be defined entirely before processing the input message and should be dependent on this message. We present the structure of the algorithms, results of computational experiments on them, and in Appendix we give procedures implementing the hash functions.