{"id":4953,"date":"2026-06-15T11:29:47","date_gmt":"2026-06-15T09:29:47","guid":{"rendered":"https:\/\/www.manage-now.de\/?p=4953"},"modified":"2026-07-01T14:21:00","modified_gmt":"2026-07-01T12:21:00","slug":"harvest-now-decrypt-later-why-migration-to-post-quantum-cryptography-must-begin-today-not-only-once-quantum-computers-are-operational","status":"publish","type":"post","link":"https:\/\/www.manage-now.de\/en\/blog\/harvest-now-decrypt-later-why-migration-to-post-quantum-cryptography-must-begin-today-not-only-once-quantum-computers-are-operational\/","title":{"rendered":"Post-Quantum Cryptography: Why IT Decision-Makers Must Act Now\u2014Not When Quantum Computers Become Operational"},"content":{"rendered":"\n
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Post-Quantum Cryptography (PQC) is no longer a future option\u2014it is an immediate security necessity. State actors are already harvesting encrypted data today with the intention of decrypting it once quantum computing reaches a breakthrough. The real urgency is not driven by the quantum computer itself, but by the time required for migration: typical migration projects take five to ten years. Organizations that do not start now are unlikely to complete the transition in time. <\/em><\/p>\n <\/div>\n \n <\/div>\n<\/section>\n

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Why Is Today's Encryption Threatened by Quantum Computers?<\/h2>

The Public Key Infrastructure (PKI), which underpins a large portion of digital security, is based on mathematical problems that classical computers cannot solve within a practical timeframe: the factorization of large integers (RSA) and the discrete logarithm problem (Elliptic Curve Cryptography, ECC). A sufficiently powerful quantum computer can solve these problems in polynomial time using Shor\u2019s algorithm. <\/p>\n

This means that every digital signature, key exchange, VPN connection, and TLS certificate based on RSA or ECC is vulnerable to attack by a sufficiently powerful quantum computer. In addition, Grover\u2019s algorithm weakens symmetric encryption algorithms such as AES, making the use of longer key lengths necessary. <\/p>\n

For IT decision-makers, this means that the entire existing cryptographic infrastructure will need to be replaced over the medium term. The question is no longer if this transition will happen, but when\u2014and how systematically it can be managed. <\/p>\n <\/div>\n \n <\/div>\n<\/section>\n

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What Is \u201cHarvest Now, Decrypt Later\u201d \u2013 and Why Is the Risk Already Real Today?<\/h2>

The most immediate risk posed by the quantum threat already exists today. The so-called \u201cHarvest Now, Decrypt Later\u201d scenario describes an attack strategy that is actively being used: state actors and highly motivated attackers systematically collect encrypted data\u2014including communications, documents, and transactions\u2014with the intention of decrypting it once quantum computers have achieved the required level of computational power. <\/p>\n

For organizations that handle data requiring long-term confidentiality, this risk is already material today. The following are particularly affected: <\/p>\n