Wild Rogue by Louise Rose-Innes

Rose Wilde lost her husband on their honeymoon in the Tunisian terror attack five years ago and has never fully recovered. Filled with rage, she joined the British army – more specifically, the special forces reconnaissance regiment – where she became an expert at hiding her emotions and pretending to be someone else. Now part of the SAS Rogue Unit, she’s been assigned to protect a cryptocurrency developer who is being targeted by a ruthless arms dealer. Except she has to do it as his wife.
Damian Clayton was married two days before his wife ran off and left him. But he’s not your typical computer geek. He’s got a shady past and his cryptocurrency has enabled criminals to thrive on the dark web. Now he’s making a change. A new upgrade that will peel back the layers of secrecy and expose the user’s real identities – if he can live to implement it. Having sworn off women, Dorian is horrified to learn that his protection detail will be posing as his new wife. And he’s even more horrified by how helplessly he’s attracted to her.