982
The Turkish - American cryptographer , who identified critical vulnerabilities in Ethereum ’s codebase before its network was hit with the DAO attack , was referring to all the currently 69 active bitcoin forks that could still be exploited with a 51 % attack as their clients might still not have received a patch and are not as secure as bitcoin network due to their smaller size .
 discover vulnerability: be exploited
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: phishing, data breach, ransom, discover vulnerability, patch vulnerability 
Text: {0} 
Answer:
 discover vulnerability: be exploited