Cyber security increases in complexity and network connectivity every day. Todays problems are no longer limited to malware using hash functions. Interesting problems, such as coordinated cyber events, involve hundreds of millions to billions of nodes and similar or more edges. Nodes and edges go beyond single attribute objects to become multivariate entities depicting complex relationships with varying degree of importance. To unravel cyber securitys big data, novel and efficient algorithms are needed to investigate graphs and signatures. We bring together domain experts from various research communities to talk about current techniques and grand challenges being researched to foster discussion.