Secure Connections 

9. In 

the 

Confirm passphrase box, enter your passphrase again. 

10. Select OK. 

C

ONFIGURATION 

N

OTES

Your private key and passphrase are never transmitted over a connection. When the server 

attempts to authenticate: 

1.  The server encrypts a random number with your public key and sends it to you. 

2.  If you have not entered your passphrase in SSH2 security settings, CuteFTP asks 

you for your passphrase to activate the private key. 

3.  The private key decrypts the number and sends it back to the server. 

4.  The server recognizes the number as correct and allows the connection. 

Public key authentication 

To use public key authentication, you must send your public key to the server administrator 

before making an SSH2 connection. If the server is running OpenSSH, you must  convert 

the public key as described below: 

1.  Create an identity file in the client. 

2.  Send the public key (Identity.pub) to the server administrator (via FTP, e mail, etc.) 

3.  The server administrator must convert the public key to OpenSSH, check it with 

wordcount, and add it to authorized_keys.  

Command sequence: 

ssh keygen  i  f Identity.pub > sshpub 

wc sshpub 

cat sshpub > ~\.ssh\authorized_keys 

Note: 

Wordcount should return a "1" as the first number. OpenSSH asks for 

the identity files password the first time you log in. If CuteFTP fails to 

connect, contact our support team and provide the kernel version, 

OpenSSH build, and the CuteFTP Professional build number (located 

under Help > About). 

Troubleshooting SFTP Connections 

If you are having difficulty connecting to your SFTP server: 

1.  Verify that the server you are connecting to supports SFTP connections. 

Note: 

CuteFTP Professional supports SFTP, a secure service provided by the 

SSH2 host in which the server both encrypts the data and handles the file 

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