Why Quantum computing is changing cybersecurity
The entire digital world—from online banking and cloud logins to government communications—is based on asymmetric cryptography, such as RSA and ECC. These methods are considered secure today because it would take an enormous amount of time for a classical computer to solve the underlying mathematical problems, such as prime factorization.
The Breakdown of Trust: Quantum computers use specialized algorithms, such as Shor's algorithm, that can theoretically reverse these mathematical "one-way functions" in a matter of minutes. As soon as a sufficiently powerful computer exists, the foundation of public-key infrastructure (PKI) will collapse. This puts key security mechanisms under pressure:
- Data encryption
- Digital signatures
- and authentication systems.
The consequence? Public-key cryptography, which secures the web and banking, requires a new mathematical safeguard.
The underestimated threat: Harvest now, decrypt later
One of the greatest dangers is not an immediate attack, but rather a gradual one. Attackers follow the strategy of "harvest now, decrypt later" (HNDL):
- Harvest: Encrypted data streams are currently being intercepted and stored on a massive scale.
- Decrypt: As soon as quantum hardware is ready, this data will be decrypted retroactively.
This is particularly critical for information with a long retention period.
