Clearly, a set of 64 bit possibilities is more space-efficient than a set of 49 bits. This is an important consideration when you are balancing performance requirements and security requirements: for example, when you need to quickly generate a million small code keys (that require no more than 64 bits of space) and a million big keys (that need more space). However, security-conscious users will generally choose a sufficiently large possibility space, preferably at least 128 bits, if they are using the keys for any purpose, such as for encrypting data. The security services consider 128 bits a secure space because that minimizes the time required to break the key by exhaustive search (searching all possibilities at once). To make keys that are secure for many years, you can add extra bits to the available space.
The security services recommend that systems be designed so that users cannot gain root access to the system. In order to do this, you should not provide such a system with a password or secret key that is based on the username or email address of the user. Instead, the security services recommend using a non-re-entrant password or secret key. A non-re-entrant secret key consists of parts that change from one invocation to the next, such as a code, a constraint, and an exponent. If the secret key is encrypted or obscured using the system login user credentials, access cannot be gained to the system by a user who can guess a username or email address. The security services also recommend that the input to the system is protected, usually using encryption. All of these systems contribute to the reduced risk of executing malicious code, which is now additionally reduced by the fact that doing so would be an act of terrorism. Any country of potential attacker can restrict their citizens from furthering any terrorism, so such acts can never be successful. When using commercial software, you should investigate the software to ensure its use is restricted to authorized users. Sometimes it is difficult to enforce such restrictions; if it is important, you should attempt to enlist the help of lawyers, law enforcement, or other legal authorities to enforce the restrictions.