Which is Higher: AS2 vs. SFTP?
Over the last several months, we’ve compared many different file transfer protocols, including SFTP vs. FTPS and SFTP vs. MFT, and MFT vs. Dropbox for secure file sharing.
Today, we’re going to look at AS2 vs. SFTP. How do these popular file transfer protocols work? How do they differ? And most importantly, which one is better for your organization’s file exchange requirements?
What is AS2?
AS2 stands for Applicability Statement 2. Originally, Applicability Statement was created in the 1990s as AS1. It was later upgraded when Walmart adopted and required their suppliers and other third-party vendors to use it in 2002. The upgrade included the encryption of messages, known as AS2 messages, that were exchanged with trading partners, vendors, and remote systems using a secure HTTPS connection. AS2 remains very popular among retail organizations, especially those that detail with e-commerce, today.
AS2 employs two security methods to protect sensitive information in transit: digital certificates and industry-level encryption standards. All AS2 messages exchanged over HTTPS are compressed and signed before they’re transmitted via a secure SSL tunnel.
When compared to secure file transfer protocols like FTPS and SFTP, AS2 has a feature that makes it unique: it allows users to request a Message Disposition Notification (MDN), also known as a receipt, that alerts the sender once the message has been received and decrypted by the recipient. This receipt (also called an NRR, or non-repudiation of receipt) is created, signed, and returned to the sender after decryption, giving them legal proof that the file was delivered without being altered in transit.
What is SFTP?
SFTP stands for FTP over SSH. It is a secure FTP protocol, which means SFTP is an excellent alternative to unsecure FTP tools or manual scripts. SFTP exchanges data over a secure shell (SSH) connection and provides organizations with a high level of protection for file transfers shared between their systems, trading partners, employees, and the cloud.
For encryption, SFTP supports AES, Triple DES, and similar algorithms like Blowfish. For authentication, organizations that implement SFTP can test a connection using a user ID and password, an SSH key, or a combination of an SSH key and password.
When to Choose AS2 vs. SFTP
So, when should you choose AS2 or SFTP for file transfers? Here are some considerations:
Choose AS2 if…
Choose AS2 if a) you are a retail or e-commerce organization or b) you need an easy way to meet regulatory compliance requirements and trading partner needs. Synchronous or asynchronous MDN receipts, especially, help prove that file transfers have been received and decrypted successfully—and by the right person.
AS2 also offers benefits like:
- End-to-end file encryption
- Validation of file integrity with successful transfer confirmation (non-repudiation)
- Ability to send or retrieve files of any size or volume
AS2 software can also be Drummond Certified. Drummond Certified is a label that Drummond Group, a third-party certification organization, gives to any solution that can prove interoperability between AS2 vendors. The certification is extensive and ensures that the solution you use will allow you to integrate with your AS2 trading partners.
Learn More: AS2 Client and Server Transfers
In order to achieve certification, the solution’s vendor must conduct thousands of AS2 protocol test scenarios successfully. This process uses full matrix interoperability testing between AS2 vendor solutions to verify that important transfers maintain their security and integrity as they are exchanged across secure internet connections.
Choose SFTP if…
The rest of the business world tends to prefer SFTP over AS2. Choose SFTP if you need strong authentication and firewall options. With SFTP, you can use a user ID and password or use SSH keys with (or in place of) passwords to authenticate a server-to-server connection.
While authentication with SSH keys requires you to generate SSH key pairs, secure file transfer solutions like EDI Here offer key and certificate management systems (often abbreviated as KMS) alongside a SFTP client or server to help keep the organization’s SSH keys secure, organized, and stored in a central location.
SFTP is also easy to implement. Since it’s a firewall-friendly protocol, it only needs one port opened (usually port 22) to send initial authentication requests, issue commands, and exchange information between your organization and another server.