Ask, and the universe provides. My first actual post to SN was one asking about Bitcoin in fiction, and then an author I'm already a fan of turns out to have a book I'd missed that does have Bitcoin (in a minor role) in it!
Ruth Ware's become one of the big names in the British (and to a lesser extent, the global) crime scene. She's often called the "New Agatha Christie," but I find that reductive and kind of insulting to both of them. Ware's not about recurring detectives like Poirot and Marple, but more about ordinary people caught up in big events. Hitchcock's probably a better comparison.
She's dealt with tech in her books before -- One by One, a nifty crime novel set at a snowed-in ski lodge, is about the execs at a company working on a successful social media tool -- but Zero Days has pen testing as a core plot point, and could almost be classified as a techno-thriller. More importantly, though, it's fun and a good read.
The plot: Jacintha "Jack" Cross is part of a two-person penetration testing team with her husband, Gabe. Gabe's the hacker of the two, running code and trying to break through digital defenses, while Jack's the one doing the in-person work, breaking into facilities to test them, leaving USB drives in the parking lot, etc. One night, she gets caught by a security guard, and while she's sorting things out at the police station (contacting the CSO to confirm she was there legitimately) and then taking a long drive home, her husband is brutally murdered.
She not only has the trauma of discovering his body, but soon enough, realizes she's the prime suspect, as the knife (from their kitchen) has her fingerprints on it, and Gabe seems to have opened up a brand new life insurance policy with Jack as the beneficiary. Sure that if the police take her in, the frame will be complete, she goes on the run, injuring herself in the process (a wound that gets worse and worse through the book, eventually leading to sepsis).
Jack's a fun protagonist. She's able to use a ton of her pen testing skills when hiding, from bluffing her way into facilities to finding passwords through social engineering -- but since her husband was the tech whiz, can't rely on hacking skills (or worse, fictionalized "magic hacking" skills that are so common. She's forced to improvise, even as her health's getting worse and her ability to navigate around London (with its ubiquitous surveillance) gets more and more restricted.
There's a good supporting cast -- essential in any thriller, since "who can you trust?" has to be a recurring question -- and the pace ramps up quickly as Jack goes on the run. The "who" part of the whodunit element is always the least interesting things to me, since I read so many crime novels that I'm reasonably good at intuiting it, but the "how" and the "why," along with how the protagonist puts it together, are what I enjoy. This one has a solid dénouement and ending, and wraps things up nicely.
BTC itself is essentially treated as a valued asset here, not really vital plot element, but it fits in with the characters and setting, and is used realistically (for starters, it's actually Bitcoin and not some BS coin made up for the book). At one point, she's aware of how KYC will nail her: "I had Gabe’s Bitcoin, of course, but I was fairly sure that no reputable exchange would start handing out cash—not without showing ID, anyway." At another, she ends up agreeing to something in fiat and realizing after the fact that BTC's exchange rate fluctuates. Not a reason to read the book, but definitely a nice addition.