  ALGORAND is a celebrated public ledger technology. In this paper, we identify
several design flaws of the ALGORAND protocol. In particular, we show that the
claimed (proved) fork-free property is not true and several assumptions in
ALGORAND are not realistic in practice. The ALGORAND wiki page
https://golden.com/wiki/Algorand claims that "the probability of a fork in the
protocol is estimated at 1/1,000,000,000 and therefore blocks can be considered
final upon validation". However, our first attack in this paper shows that a
malicious adversary who controls less than 1/3 of the users (or money units)
could fork the ALGORAND chain very easily. Our second attack shows that a
malicious adversary could use a bribery attack to fork the ALGORAND chain very
easily also. Furthermore, we show that the celebrated Byzantine Agreement
component in ALGORAND is not necessary. The Byzantine Agreement is the most
expensive part and one of the most innovative parts in the ALGORAND protocol.
It is used to avoid forks in ALGORAND. We show that a simple majority vote
could be used to achieve the same property that Byzantine Agreement achieves in
ALGORAND under the same network assumption.
