Secure Asynchronous File Transfer


Secure Asynchronous File Transfer – SAFT


“Payload encrypted bittorrent like protocol for robust file transfer”


Sending files or large chunks of data between two endpoints requires a secure tunnel with both parties awake and connected at the same time. This can be difficult in a mobile connection, especially if a device saves battery by staying asleep as much as possible.

HYKER has implemented a specific protocol to solve this problem; SAFT – Secure Asynchronous File Transfer. This means that the sending device just encrypts and sends the file disregarding if the recipient is online. It also handles the case of a recipient dropping out in the middle of a transfer. The parts not received is kept waiting in a secure cloud-based queuing system in encrypted and non-accessible format. When the recipient comes online the queues are read and emptied.

Robust File Transfer

  • Send file anytime
  • Recipient starts receiving when connected
  • Large files are chopped in small fragments, no need for complete file resend when dropped connection
  • Buffer(s) can be deployed on any server, data center or cloud
  • Any IP network can be used for transport

End-to-end encryption

  • No need to trust networks, relaying hubs, routers, etc.
  • No need for secure tunnels where both sender and receiver must be online at the same time
  • A file can only be decrypted by the right receiver since all receivers have unique encryption keys
  • Not possible to read, manipulate or replace files in transfer
  • Send files to one or group of receivers


SAFT example: firmware update to vehicle

Other implementations can be, for instance:

  • Distribution of sensitive documents that shouldn’t be stored on cloud services
  • System integration of batch generated data files

More reading

Take me to the documentation for a more in-depth description