Zcash is a privacycoin which, unlike popular blockchains like Bitcoin and Ethereum, allows users to obscure who they are sending money to and how much. Since June or July, the network has been suffering from a spam attack in which attackers have been submitting massive transactions that quickly fill up block space. The chain has exploded in size, nearly tripling to more than 100GB since the attack began. Unlike other chains which are prohibitively expensive to attack, each spammed transaction costs less than a cent, and the attacker is estimated to be spending roughly $10 a day to execute the attack.