Every “unbreakable” cipher has had an expiry date.

We are named after Friedrich Wilhelm Kasiski, who in 1863 published the method that broke the Vigenère cipher. Today, RSA and elliptic-curve cryptography have an expiry date too. We help institutions replace them in time.

From Al-Kindi to Kasiski

c. 850
Al-Kindi, Baghdad
Count the symbols
Al-Kindi wrote the oldest known description of frequency analysis. In a long ciphertext, the most common symbols stand for the most common letters. It is the founding method of cryptanalysis.
Al-Kindi, On Deciphering Cryptographic Messages
- H19=e
- U7
- W7
- G7
- V6
- D6
- K6
Letter counts in a substitution cipher. The most frequent symbol gives the first letter away.
1863
Friedrich Wilhelm Kasiski
Measure the repeats
Kasiski published Die Geheimschriften und die Dechiffrir-Kunst and broke the Vigenère cipher, called “indecipherable” for three centuries. Repeated sequences in the ciphertext reveal the length of the key.
Kasiski, 1863
The same sequence, 18 letters apart. The key length divides 18.
Today
RSA and elliptic-curve cryptography
Replace the keys
Estimates of the qubits needed to break RSA‑2048 fell from about 20 million to under one million. The replacements are standardised. The work now is to put them into every system in time.
Gidney and Ekerå, 2019; Gidney, 2025; NIST, August 2024
Today’s keys and their standardised replacements.

Cryptographic sovereignty means knowing, owning and being able to change the keys your future depends on.

What we offer: The expertise to apply the new standards safely across every system, vendor and team.
What we do not offer: The algorithms. ML-KEM, ML-DSA and SLH-DSA are public NIST standards, and that is a strength.
How we work: Inside your boundary. Your data stays in your jurisdiction, and we never name a client without permission.