Blockchain Technology

Blockchain is a technology for storing and transmitting information that is transparent, secure and operates without a central control body.

We secured access, “Trust by design” and integrity through the Blockchain KSI

Sustainable technology

Public blockchains - especially those linked to applications such as crypto-currencies - are regularly criticized for their ecological impact (excessive consumption of electricity due to energy-intensive consensus protocols in particular).

The KSI blockchain is based on mathematical algorithms that do not require significant energy resources and are not indexed to the price of a crypto-currency.


Guardtime’s KSI® Blockchain Timestamping Service is compliant with the eIDAS regulation and included in the European Trusted List.
KSI® is the first blockchain-based technology to receive an eIDAS accreditation and marks an important step in the evolution of digital trust technologies. Accreditation was conducted by TÜV Nord, Germany.

Cost effective

It is a cost-effective next-generation security solution which sets a new standard in securing sensitive paper-based and digital documents, credentials and qualifications.

Immediate access to a simple and cost-effective online service for managing secure certificates, no infrastructure required;

What is the KSI Blockchain ?

A blockchain is a trust anchor which secures the integrity of any given data. SwissTruthTM is based upon the KSI blockchain which assures data integrity and authenticity by underlying mathematic proofs. No individual party can change or manipulate data and processes once it is secured by the KSI blockchain.

KSI Blockchain advantages


Application Agnostic


No data sharing/exposure


Full scalability (1012/s)

Settlement time : 1 second

Public Trust Anchor


No electricity consumption


No Cryptocurrency


Quantum Proof

Fully interoperable

Running 24/7 since 2008

How the KSI Blockchain works – Video

KSI history

The KSI Blockchain was invented in the late 1990s / early 2000s by Estonian cryptographers.

The first patent was filed in 2002 and it was launched in early 2008 in an initial pilot for the Estonian Government. Since 2012, all transactions between the different databases of the various Estonian administrations are secured via the KSI Blockchain.

Since then, the technology has been accredited by three other major governments and secures billions of documents, also for other public and private entities around the world.

In early 2020 the KSI Blockchain became the first blockchain-based trust service certified under the EU’s EIDAS framework (EU-eIDAS).

Guardtime & KSI e-government timeline

A different blockchain technology approach
designed for enterprise data governance

Open source
Public Token technology


A unique and public register
for all organizations and companies

Private Token technology

(Sensitive data)

One private register
per company

How is process integrity guaranteed?

Our technology protects the integrity of the issuing process by generating irrefutable proofs at each step of the secured process. Prior to changing any state, the current environment is verified to make sure no irregular changes have affected the integrity of the data process. The state change is then triggered following the process definition and the new state and environment is secured by a new layer of proofs. The cumulation of all the proofs guarantees the integrity of the issuing process.

Is data publicly available on the blockchain?

Personal or sensitive data is never shared with the blockchain, but only a hash form of this data which is secured by the blockchain to ensure its lifelong immutability. Only the digital KSI seals needed for verification are stored at a minimum on our servers.