Abstract: Systems and techniques are described herein for validating one or more requests. For example, the systems and techniques can include receiving message data from a first device accessible to a user. The message data can be associated with a message to be sent using the first device. The systems and techniques can also include sending, to a second device accessible to the user, a request for confirmation that the user requested a digital signature for the message, the first device and second device being different devices. The systems and techniques can further include receiving a confirmation from the second device, the confirmation confirming that the user requested the digital signature for the message. The systems and techniques can further include generating the digital signature for the message using the message data and a private key and sending the digital signature to the first device.