We’re proud to announce the release of AbsoluteTelnet/SSH version 13.13, the newest update to our trusted Windows SSH and SFTP client. This release introduces cutting-edge security features, improved file-transfer performance, and expanded compatibility with next-generation cryptographic standards — all while maintaining the rock-solid reliability AbsoluteTelnet is known for.
🚀 What’s New in 13.13
1️⃣ AEAD Encryption for Performance and Security
AbsoluteTelnet now includes full support for authenticated encryption with associated data (AEAD), including AES-GCM and other modern modes.
AEAD ensures both confidentiality and integrity while reducing CPU overhead, leading to faster and more secure connections. This update is fully compatible with a wide range of SSH implementations — OpenSSH, Dropbear, and others — ensuring seamless interoperability across platforms.
2️⃣ Hybrid Post-Quantum Key Exchange (PQ KEX)
Version 13.13 adds support for hybrid post-quantum key exchange algorithms, combining the best of classical elliptic-curve cryptography with quantum-resistant methods.
Now supporting:
- ML-KEM (Kyber) — the NIST-standardized key encapsulation mechanism for quantum-safe encryption
- sntrup761 (NTRU Prime) — a compact, efficient lattice-based algorithm widely deployed by OpenSSH
These algorithms protect session keys from potential quantum decryption in the future, while maintaining full backward compatibility with existing servers. Whether you connect to modern OpenSSH deployments or mixed environments, AbsoluteTelnet 13.13 negotiates the strongest possible key exchange automatically.
3️⃣ Optimized SFTP Transfer Throughput
SFTP now supports virtually unlimited window sizes, enabling dramatically higher throughput for single-channel transfers. You’ll notice faster upload and download speeds, smoother directory browsing, and much better efficiency over high-latency or high-bandwidth connections.
4️⃣ User Interface and Quality Improvements
- Modernized tab control with per-monitor DPI awareness
- Cleaner font rendering and layout precision
- Smarter defaults for common SSH and SFTP settings
🔐 Still the Most Flexible Windows SSH Client
AbsoluteTelnet continues to deliver the broad feature set professionals depend on:
- SSH1 / SSH2, Telnet, Serial, and TAPI connections
- Smart card, Kerberos, and GSSAPI authentication
- VBScript automation for complex workflows
- Configurable fonts, color schemes, and key mappings
Whether you’re managing enterprise infrastructure or connecting to embedded systems, AbsoluteTelnet/SSH provides the speed, flexibility, and security your work demands.
💡 Why Professionals Choose AbsoluteTelnet Over PuTTY
AbsoluteTelnet isn’t just another terminal client — it’s a professional-grade SSH solution.
Compared to PuTTY, it offers:
- Integrated SFTP file transfer
- Smart card and GSSAPI authentication built in
- Full-screen color customization and layout flexibility
- Direct developer support and active maintenance
📦 Get Version 13.13 Today
Try AbsoluteTelnet/SSH free for 30 days or upgrade your existing license today:
👉 Download AbsoluteTelnet 13.13
👉 Buy Now
Existing customers can install this version directly over their current installation — all preferences and licenses remain intact.
🧰 System Requirements
- Windows 10 / 11 / Server 2016 and newer
- 64-bit CPU recommended for optimal performance
⭐ About Celestial Software
Celestial Software develops professional-grade communication tools for Windows, including AbsoluteTelnet/SSH, used worldwide across IT, manufacturing, retail, and hospitality sectors.
Visit www.celestialsoftware.net for downloads, documentation, and support.