Grandfather Anonymous - Old Code, #1

Elderly, unarmed, and extremely dangerous. Ajay Andersen was the best hacker the NSA had ever hired. He sank corporations, toppled governments, and broke cryptography. All of it. Retirement hasn't slowed him down one bit, thank you very much. His granddaughters are threatened, and he's going to need to step it up a notch. Biotech corporations and criminal enterprises hold the keys to survival, but ubiquitous surveillance threatens to reveal Ajay's every move.
Ajay would do anything to protect his family, but the more he digs, the more he dredges up the shadows of his own dangerous past. He only needs to know one thing: What makes his granddaughters so darn dangerous?