Keyless Signature Infrastructure



Keyless Signature Infrastructure (KSI) is designed to provide scalable digital signature based authentication for electronic data, machines and humans.

Unlike traditional approaches that depend on asymmetric key cryptography, KSI uses only hash-function cryptography, allowing
verification to rely only on the security of hash-functions and the availability of a public ledger commonly referred to as a blockchain.

A blockchain is a distributed public ledger; a database of transactions such that there is a set of pre-defined rules as to how
the ledger gets appended, achieved by distributed consensus of participants in the system.With KSI, history cannot be rewritten.

Get in touch now with the developers of the Keyless Signature Infrastructure!


Keyless Signature Infrastructure is one of the Components that make up the digital society of Estonia. This e-solution is provided by the company Guardtime.



Introduced in: 2007


  • Citizen Empowerment. Each citizen gains an ability to verify the integrity of their records at government databases at will, independently of the government or any other third party.
  • Government Accountability. KSI makes it impossible for privileged insiders to perform illegal acts inside the government networks, and erase the log evidence pointing to their actions without it being immediately evident.
  • Long-term Data Integrity Since KSI is based solely on hash-function cryptography, it will not be vulnerable to attacks utilizing quantum computing, unlike RSA-based digital signature schemas.

Did you know?

… that KSI is the only provably secure digital signature schema? … that KSI instrumented data can be verified even offline, based on a control publication printed in physical newspaper? … that KSI can today sign trillion (1 000 000 000 000) data items every second - that’s more data than what is produced in the world, combined?

Featured Case Studies