Many individuals, businesses and other organizations have
a legitimate and lawful need to keep some of their information confidential or even absolutely secret from competitors, the press and others. Because email
has become vital to timely communication and because email is not secure, encryption is often necessary.
New employees of large companies are often encouraged
to live near the company's offices. In this kind of setting, privacy for technical and marketing information is convenient. Small organizations such as law
offices, medical clinics, Internet businesses, and many others may not find the expertise they need in their local area. These small organizations, of which
there are many, need secure communication to avoid the cost of face-to-face meetings. Lacking the funds for routine flights between cities, these
organizations are very dependent on the electronic communication of data and ideas. Private medical information, schematic drawings, program source
code, marketing plans, and innumerable other types of documents are involved. In such circumstances, strong encryption is needed.
In many countries, the post office has the legal authority
and obligation to enforce privacy for the postal mail. If these postal services were to offer secure email for a reasonable price, small companies would not
be at such a disadvantage relative to larger companies.
Established by the U. S. Constitution, Article I, Section 8,
Clause 7, the United States Postal Service is authorized "To establish post offices and post roads. It also has a long history of adding services as needed, such
as commemorative stamps, rural delivery, airmail, one-day delivery, zip codes, self-adhesive stamps, public Internet site, “Forever” stamps, and an iPhone
app. Secure communication would add to its revenue (which would help ameliorate its recent shortfalls) and set a good example.
To create a secure message, the encryption algorithm
must use secret information that cannot be discovered by unauthorized parties. If the encryption relies only on complexity or computational difficulty
without involving secret information, the intended message can be discovered by third parties. To third parties, some aspect of the transmission must be
Within encryption technology, the embodiment of
information unknowable to third parties often takes the form of secret random numbers. These random numbers are used to encrypt messages in such
a way as to make decryption of a message impossible without access to those same random numbers.
Many have said that what one person can encrypt, another
can decrypt. This is a myth. The One-Time Pad
algorithm was proved to be absolutely secure in the writings of Claude Shannon. See "Claude
Elwood Shannon - Collected Papers" edited by N. J. A. Sloane and Aaron D. Wyner. In addition to being immune from hacking, this algorithm becomes
more convenient as memory devices increase their capacity.
Claude Shannon proved that any encryption algorithm
possessing these characteristics is absolutely secure:
1. The encryption keys must
be random numbers of uniform distribution.
2. The keys must be shared in
absolute secrecy by the sender and receiver.
3. Any key encrypting a
message must be as at least as long as that message.
4. Any key used to encrypt a
message must not be reused.
The one-time pad is a famous encryption algorithm
having all of these characteristics. By using a random key comprised of random numbers to encrypt a message (the plain text) with the XOR logical
operation, the transmitted result (the ciphertext) is rendered as random as the key. The collection of secret keys is called the pad
. Keys are of
the same length as that of the messages they encrypt. They are erased immediately after their use. The result is that the actual message is as likely as
any other message from the point of view of those attempting to decrypt the message without knowing the secret random numbers.
Optionally, encrypted messages can be made to appear
to be ordinary messages of a different type, such as pictures or sound files or text messages that contain information that is very different form that in the
plain text. This process is called Steganography
The most important service
facilitating secure communication is the shipping of media containing random numbers. The production of truly random numbers for algorithms
that encrypt messages by means of random keys is the part of the process most challenging and inconvenient for the customer. The principle service
of USPS would be to place random numbers on appropriate media and ship copies to addresses designated by the customer. One shipment might serve
the customer for only a few messages or for years worth of messages, depending on the number of random numbers shipped.
Options may include picking up
shipments from the local post office, receiving them in the mailbox, or receiving them at the recipient's door (possibly by special delivery or with a return
Measures which distinguish legitimate
from nefarious use of encryption services need not be publicly discussed.
Please feel free to make suggestions
by writing to firstname.lastname@example.org