SAP Adds Post-Quantum Handshake to S/4HANA to Counter Harvest Now, Decrypt Later Attacks

SAP has added post-quantum key exchange to SAP S/4HANA across its Public Cloud, Private Cloud, and on-premises deployments, along with the ABAP environment on SAP Business AI Platform. Version 8.6.2 of the SAP Cryptographic Library targets “harvest now, decrypt later” attacks, in which an adversary records encrypted traffic today and decrypts it once a quantum computer can break the key exchange.

Activation is automatic once the library and a compatible kernel are in place, which shifts the work for SAP teams from configuration to patching and exception handling.

How the Hybrid Handshake Works

A Transport Layer Security (TLS) connection begins with a handshake in which two systems agree on a session key. SAP notes that a sufficiently large quantum computer running Shor’s algorithm can break the elliptic curve exchange TLS has long relied on, exposing the keys behind stored traffic. Version 8.6.2 runs that classical exchange alongside Module-Lattice-based Key Encapsulation Mechanism (ML-KEM), a post-quantum algorithm standardized as FIPS 203.

The session key stays secure as long as either algorithm holds, a design SAP describes as industry best practice for the transition. Early migration work centers on key exchange, in SAP’s account, because the handshake protects confidentiality in transit: a recorded session is exposed from the moment it is sent.

The exchange needs library version 8.6.2 or higher and a kernel that supports TLS 1.3. Public Cloud and ABAP environment kernels already have TLS 1.3 enabled by default, while Private Cloud and on-premises customers check kernel versions against an SAP Note. Once the library and kernel are in place, the exchange activates automatically on TLS 1.3 connections whenever both endpoints support it.

Where Third-Party Connections Need Attention

Connections between SAP components need no adjustment, SAP says, but some non-SAP systems may reject the new handshake. An ML-KEM key share runs to several kilobytes, against a few dozen bytes for a classical elliptic curve share, and not every TLS implementation handles a payload that size. Failed handshakes or dropped connections after the upgrade likely point to the larger key size.

SAP advises switching off the post-quantum exchange for affected destinations only. In Public Cloud and the ABAP environment, where profile parameters are out of reach, that means configuring the communication system for TLS 1.2, which gives up TLS 1.3 for that destination. Private Cloud and on-premises systems can disable ML-KEM alone for individual destinations and keep TLS 1.3.

SAP Is Adding Post-Quantum Protection Layer by Layer

The S/4HANA update covers one layer in a stack where SAP has been adding quantum-resistant protection in separate places. SAP uses Adva Network Security’s Layer 1 encryption, which Adva describes as combining established and quantum-secure cryptography, on the fiber between its Walldorf and St. Leon-Rot data centers.

SDxCentral reported that SAP also updated SAP HANA Cloud with a hybrid key exchange for TLS connections. The outlet adds that Microsoft, a long-time SAP partner, accelerated its Quantum Safe Program timeline to a 2029 transition.

In the SDxCentral article, Mark Pecen, chair of the European Telecommunications Standards Institute’s quantum technology committee, noted that a U.S. executive order requires federal agencies to move high-impact systems to post-quantum key establishment by December 31, 2030. Key establishment covers the key exchange that the S/4HANA update changes.

What This Means for SAPinsiders

Key exchange leads early post-quantum migration. Data sent under a classical handshake stays exposed for as long as it must remain confidential. SAP aimed this protection at the point where that exposure begins, tying migration timing to the shelf life of the data.

Exception handling becomes the working task. Because the exchange switches on by itself, open questions sit with connections that cannot handle it. In public cloud systems, resolving one means moving that destination to an older TLS version, which forgoes post-quantum protection there.

Quantum protection is moving through the stack. SAP is adding post-quantum protection at the data center link, the database, and the application, so coverage differs by layer. Federal timelines for key establishment, set by executive order, give that layering weight for federal agencies.