Elanie Brown

PuTTY is a versatile terminal program for Windows. It is the world's most popular free SSH client. It supports SSH, telnet, and raw socket connections with good terminal emulation. It supports public key authentication and Kerberos single-sign-on. It also includes command-line SFTP and SCP implementations. Features Windows client. Mac and Linux ports exist. No server included. Supports both 32-bit and 64-bit Windows. An MSI installer has been available since 2016. Supports SSH client, telnet client, SFTP client (command line only), and rlogin client. Both SSH2 and SSH1 protocols are supported. Note that the use of SSH1 is not recommended for security reasons. Practically all devices support SSH2 these days. Supports public-key authentication and Active Directory/Kerberos authentication. File transfers only using a separate command-line program. No integrated file transfer support. No scripting support, but can be used together with WinSCP. Terminal window The main feature of the product is the terminal window. It has good terminal emulation, good configurability, and good support for different cryptographic algorithms. SSH, telnet, and plain TCP/IP protocols are supported. The PuTTY terminal is pretty good and handles terminal emulation well. Transferring files The user interface does not include an integrated file transfer client. However, command-line tools called PSFTP and PSCP are provided. These can be used for file transfers. However, most non-technical users are not willing to use a command line. Tectia SSH, for example, has offered fully integrated file transfer capability since 2000. History and maintenance status PuTTY is one of the oldest SSH clients for Windows. It was first released by Simon Tatham in 1998. SSH support was added in 2000. After 19 years, the software is still a beta version. The development has been slow, but it is still being maintained. A recent version added support for elliptic curve cryptography. The user interface or features have not changed much in 15 years. Telnet support PuTTY grew out of a telnet client. It still supports the telnet protocol. However, very few devices use telnet these days. Its use is not recommended for security reasons. Telnet sends all user names and passwords in the clear. It is very easy to listen to network traffic and steal user names and passwords from telnet traffic. By the mid-1990s, such password sniffing attacks had become the largest security problem on the Internet. That was the very problem SSH was designed to solve. Compromised routers, switches, or ARP proofing attacks can also be used to inject arbitrary commands into telnet sessions. There is a separate version of the software, called PuTTYtel, for countries that do not allow any use of encryption. However, SSH is now used in all countries, officially or unofficially. Most systems can no longer be managed without encryption. Even the most oppressive countries need to secure their systems windows.There cannot be cybersecurity in a networked environment without encryption. PuTTY also supports connecting to serial ports and raw sockets. These can sometimes be useful for debugging purposes and for working with some legacy devices. For example, in kernel development access via a serial port is still sometimes the best way to debug a panic that causes an immediate reboot, as it provides a way to see the boot messages.