Skip to main content

Sign message

You can use URL to sign messages. Simple example:

Messages can be signed using either Idena Web App or Idena Desktop App. It's recommended to use Idena Web App as a default method for signing messages. Users who have no Idena Web App account can sign their messages with the Idena Desktop App by clicking Open in Idena app link below.


The Idena Desktop App pops up automatically when the user clicks dna://sign/... URL.

URL format

URL example for signing messages with Idena Web App:

URL example for signing messages using Idena Desktop App:



  • message(*): message string for signing
  • format: doubleHash/prefix specifies signed data format (default: doubleHash)
  • callback_url(*): specifies URL that will be opened in the client's browser automatically after successful signing
  • favicon_url: specifies custom URL for the icon displayed for user in the Idena app

(*) - required parameter


format specifies the format of the signed data

doubleHash (default)

The message is hashed twice before signing it


The message is prepended with \x00Idena Signed Message:\n<length of message> before hashing and signing it

Callback URL

The web page specified in callback_url will be automatically opened in the user's browser once the message is signed. Callback URL example:

signature parameter specifies the signature