By default, .keystore has no password, though you normally assign it one with keytool.exe. Don’t lose the password. There is no way to recover it. You have to start over and create a new empty .keystore with keytool.exe.

.keystore is stored in a binary jks format (Java Key Store) similar to PKCS #12 containing both public and private keys, protected by a passphrase. The first four signature bytes of a Sun .keystore file in hex are FEEDFEED.

.keystore lives in your account directory e.g.: C:\WINNT\Profiles\Administrator\.keystore or C:\Documents and Settings\%username%\.keystore or in Vista in C:\Users\%username%\.keystore.

Make sure you back up your .keystore files especially when upgrading your OS or Java. Otherwise you will lose your code signing certificates.

Usually the .keystore file is stored in Sun JKS format, but keytool.exe is capable of dealing with other formats as well. Here is how to find out what other formats are supported on your platform: