Option Defaults

Here are the defaults for various option values. 
-alias "mykey"
-keyalg
 "DSA" (when using -genkeypair, except for RACF keystores)
 "RSA" (when using -genkeypair, for RACF keystores)
 "DES" (when using -genseckey)
-keysize
 Start of changes for service refresh 5 fix pack 102048End of changes for service refresh 5 fix pack 10 (when using -genkeypair)
 56 (when using -genseckey and -keyalg is "DES")
 168 (when using -genseckey and -keyalg is "DESede")
-validity 90
-keystore 
 the file named .keystore in the user's home directory, except for RACF keystores.
 For a RACF keystore you must specify -keystore.
-storetype the value of the "keystore.type" property in the security properties file,
 which is returned by the static getDefaultType method in java.security.KeyStore
-file stdin if reading, stdout if writing
-protected false

In generating a public/private key pair, the signature algorithm (-sigalg option) is derived from the algorithm of the underlying private key: If the underlying private key is of type "DSA", the -sigalg option defaults to "SHA1withDSA", and if the underlying private key is of type "RSA", -sigalg defaults to "MD5withRSA". Please consult the Java™ Cryptography Architecture API Specification & Reference for a full list of -keyalg and -sigalg you can choose from.