White PaperAS2 stands for Applicability Statement 2, an HTTP-based protocol for securely transmitting structured business data over the internet.
What Is AS2 and Why Is It Important for EDI?
AS2 (Applicability Statement 2) is a popular protocol for secure and reliable transmission of structured business data over the internet – including EDI documents. It enables encryption, digital signatures, and delivery receipts (MDNs), making it ideal for B2B communication across industries.
Key takeaways
- AS2 transfers EDI and other structured business data over HTTP or HTTPS with encryption and digital signatures.
- MDNs confirm whether a message was received successfully and help support reliable, auditable exchange.
- AS2 can be efficient and cost-effective, but partner setup, certificate management, and firewall configuration still require ongoing attention.
Introduction to AS2
AS2 is an HTTP-based protocol for securely exchanging structured business data, including EDI messages, over the internet. It uses encryption, digital signatures, and message receipts called MDNs to help trading partners send data directly, confirm delivery, and protect message integrity.
For organizations that exchange EDI with customers, suppliers, and partners, AS2 provides a widely used internet-based option for secure and traceable B2B communication. SEEBURGER supports AS2 in broader B2B/EDI integration scenarios, including managed routing and cloud-based connection options.
How does AS2 work?
AS2 creates a direct connection between a sender and a receiver over the internet. The sending system prepares the data, encrypts and signs it, and sends it over HTTP or HTTPS. The receiving system decrypts the message, verifies the signature, and returns an MDN to confirm successful delivery.
- The sending system prepares the business data and applies encryption and a digital signature.
- The secured message is transmitted over HTTP or HTTPS.
- The receiving system decrypts the message and verifies the signature.
- The receiving system sends an MDN back to confirm successful delivery.
What do you need to set up AS2?
- One AS2 identification and one certificate per participant
- The public keys for all certificates used by trading partners
- AS2-capable software
Each participant needs a unique identifier and certificate information so messages can be routed correctly and verified securely between trading partners.
What are AS2 certificates and MDNs?
What are AS2 certificates?
AS2 certificates help establish trusted, secure communication between trading partners. They can be created with in-house software or obtained from a certification authority. A valid certificate helps avoid delays or rejections caused by invalid credentials, while self-signed certificates can trigger security warnings.
What is an AS2 MDN?
An MDN, or Message Disposition Notification, is the receipt returned after a message is delivered. It confirms whether the AS2 interchange completed successfully and whether the message was received intact by the intended recipient.
What is an AS2 GLN identifier?
A GLN, or Global Location Number, is a unique identifier of up to 13 digits used to identify a company or business location. It can help route AS2 exchanges correctly between trading partners.
Which features and message types does AS2 support?
Main features
- Encryption and digital signatures for confidentiality, authenticity, and integrity
- MDNs and non-repudiation support for acknowledged delivery
- Compression to reduce message size
- Support for EDI, XML, plain text, and binary files
- Standardized headers, timestamping, and synchronous or asynchronous communication options
Common message types
- EDI data messages containing business documents such as purchase orders, invoices, or shipping notices
- MDNs, including synchronous and asynchronous acknowledgments
- Signed, encrypted, compressed, and signed-and-encrypted messages
- Receipt requests that ask a recipient to return an MDN
Where is AS2 used?
AS2 is widely used across industries including retail, logistics and transportation, healthcare and pharma, automotive, financial services, consumer packaged goods, and utilities. It is also used broadly in North America, Europe, and Asia-Pacific.
What are the benefits and challenges of AS2?
| Benefits | Challenges |
| High security through encryption and digital signatures | Point-to-point partner management and key exchange can become time-intensive |
| Internet-based transmission can lower communication costs | Firewall configuration may require open ports |
| Synchronous communication can enable real-time responses | Certificates must be renewed to avoid expiry-related errors |
| Broad use across industries supports interoperability | Scaling many partner connections increases operational overhead |
SEEBURGER supports AS2 operations with managed routing and cloud-based connection options for broader B2B/EDI integration requirements.
Frequently asked questions about EDI
What does AS2 stand for?
How does AS2 help secure EDI data exchange?
AS2 uses encryption, digital signatures, and MDNs to help protect message confidentiality, verify integrity, and confirm delivery.
What is an AS2 MDN?
An AS2 MDN is the receipt returned to the sender after delivery, confirming whether the interchange completed successfully and whether the message was received intact.
What do trading partners need before they can exchange AS2 messages?
They need AS2-capable software, certificate information, and the partner identification and key details needed to route and verify messages securely.
Which data formats can AS2 transmit?
AS2 can transmit EDI, XML, plain text, and binary files.
Why can AS2 become complex to manage at scale?
AS2 becomes more complex to manage as the number of trading partners grows because partner onboarding, key exchange, firewall configuration, and certificate renewal all require ongoing attention.
Related topics
Do you work in a sector with its own specific needs?
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