The Zcash network has been under attack since mid-June with spam transactions filling up available blockspace and bloating the size of the chain.
At less than a cent per transaction, the attacker is reportedly able to “[max] each 2mb block every 75 seconds.” Since the spam began, the chain has grown from approximately 30GB to over 100GB.
The effects so far have been minimal and the network has not experienced any downtime. However, some user wallets may experience syncing issues, as pointed out back in July by Zcash Media, who compared the spam to a DDoS attack.
Solutions proposed in the same thread also included changing the protocol’s “compression” method to reduce on-chain data storage, and the introduction of dynamic transaction fees reflecting blockspace demand. An update to the fee mechanism is currently in the works.
The current lack of a fee market on Zcash means that this attack is currently costing just $10 a day to execute. This is reminiscent of the cheap spamming of transactions that caused DDoS-like outages on Solana last year.
Privacy-focused cryptos are big news again
Chains like Zcash and Monero, which obscure transaction information such as sender, receiver, and the amount transferred, have come back into the spotlight lately.
In August, the US Treasury’s Office of Foreign Assets Control (OFAC) sanctioned addresses related to the popular privacy tool Tornado Cash, leaving users looking for other options, as well as stoking fears of network censorship on Ethereum.
Though the “attack” has yet to have serious effects, the aim may be to erode the reputation of the network in the eyes of the crypto community. For many users, security, reliability, and antifragility are among the key attributes that blockchain networks must prioritize.
Suspicions have been raised as to whether advocates of a rival blockchain are behind the spam. Though, with an estimated cost of $10 per day to clog up the chain, it’s clear this attack doesn’t require deep pockets and may simply be an effort to troll the Zcash community.
Whatever the motivation, any crypto network with the potential to be adversely affected by a hobbyist with some spare change is hardly antifragile.