Design of the protected software

Every Body wants to secure out Computer and protect Software. We can protect our password to unauthorized user here we give some technique for Computer help which is used to apply password for security. Common techniques used to improve the security of software systems protected by a password include:
• not echoing the password on the display screen as it is being entered or obscuring it as it is typed by using asterisks or circular blobs
• allowing passwords of adequate length (some legacy operating systems, including early versions of Unix and Windows, limited passwords to 8 characters
• requiring users to re-enter their password after a period of inactivity (a semi log off policy)
• enforcing a password policy to increase password strength
• requiring periodic password changes
• assigning randomly chosen passwords
• providing an alternative to keyboard entry (eg, spoken passwords)
• using encrypted tunnels or password-authenticated key agreement to prevent access to transmitted passwords via network attacks
Some of the more stringent policy enforcement measures can pose a risk of alienating users, possibly decreasing security as a result.