ssh-keygen Options (SSH, The Secure Shell: The Definitive Guide)

B.7. ssh-keygen Options

SSH2	Option	Meaning
	-1 filename	Convert SSH1 key file to SSH2
	-b bits	# of bits in generated key
N	-B positive_integer [180]	Specify numeric base for displaying key
	-c	Change comment (with -C )
	-c comment	Change comment
	-C comment	Specify new comment (with -c)
	-d	Generate DSA key
N	-D filename	Derive public key from private key file
	-e filename	Edit key file interactively
[181]	-f filename	Output filename
	-F filename	Print fingerprint of public key
	-h	Print help and exit
	-l	Print fingerprint of public key
	-N passphrase	Specify new passphrase
	-o filename	Output filename
	-p	Change passphrase (with -P and -N )
F	-p passphrase	Change passphrase
	-P passphrase	Specify old passphrase (with -p)
	-P	Use empty passphrase
	-q	Quiet: suppress progress indicator
	-r	Stir in data from random pool
	-R	Detect RSA (exit code 0/1)
	-t algorithm	Select key-generation algorithm
	-u	Change encryption algorithm
F	-v	Print version string and exit
N	-V	Print version string and exit
	-x	Convert OpenSSH public key to SSH2
	-X	Convert SSH2 public key to OpenSSH
	-y	Derive public key from private key file
	-? [182]	Print help and exit

[180]Undocumented

[181]The output filename is given as the final argument to ssh-keygen2

[182]You may need to escape the question mark in your shell, e.g., -\?