Cryptocurrency trading platform Bitfinex announced in a tweet that they been experiencing DDOS attack which affected the deposits and withdrawals for the newly listed IOTA on June 13, 2017.
Plans of tightening platform securities
According to their tweet announcement, they plan on increasing the security of the platform following the DDOS attack. An hour later, Bitfinex has announced that their system has stabilized, but will still continue to any issues.
Read more here: https://cointelegraph.com/news/bitfinex-undergoing-ddos-attack-iota-wallets-temporarily-unavailable
Studying Iota and Enigma white papers now.
Well.. looks more like a scaling issue. DDoS by new signups may be ;)