By Benjamin Wright
Email: Ben_Wright@compuserve.com
Attorney Benjamin Wright is author of The Law of Electronic Commerce (Aspen Law & Business. tel: 800-638-8437; fax: +1-301-417- 7650). For more about PenOp: <http://www.penop.com> or +1-212-244-3667.
This article provides general ideas, not specific advice on law, risk or security. If you need advice, consult a competent professional. Copy this article freely. All trademarks acknowledged.
You can now sign MSWord documents with a secure and legal handwritten signature.
Picture yourself concluding a dicey negotiation with a new business partner, Boris, with whom you've been corresponding by e-mail. You're undertaking a joint enterprise, the success of which calls for the utmost individual performance from each of you. To seal the deal, you prepare a letter in MSWord (very popular word processing program, having millions of installed users).
You're about to launch it as e-mail to Boris, but you stall. How do you sign the document to show your personal commitment and resolve? You could print it, sign it and mail it, but that is a hassle, and painfully slow if Boris receives his mail through the Russian postal system. Alternatively, you could attach to the electronic version of your document a bitmap image of your John Hancock, but that is risky, and a bit lame, because the image is just a file that can be clipped and pasted by anyone from one document to another. A hardier alternative would bind your autograph to the electronic document so that if clipped out it'd be invalid.
That's now possible with a new ActiveX component for MSWord, called PenOpr for MSWord. PenOp works with a digital pen to record your signature as it is written to an inexpensive digital tablet. PenOp charts the image of your signature as you write it and incorporates that image into the face of the MSWord document. (To see an example, download this article in MS Word 97 format from http://www.penop.com )
PenOp does yet more. As you write your signature, it measures
the time it takes for you to impart the various strokes of the
pen, which is unique to you. From the image and time data,
PenOp creates a "Biometric Token" -- a digital representation of
the signature that is cryptographically tied to your
one-of-a-kind document. The Biometric Token becomes part of
your document. When Boris gets your document, he can see that
you personalized it the same as if it were paper-and-ink. With
a viewer available no charge at If the document were changed, he -- or an observer such as a
court -- could tell. Boris could compare your signature to
other electronic or paper signatures he may have from you. If
he is of a mind to do it, he could even seek verification of your
signature with the aid of a handwriting expert. When he gets
your document, would Boris be required to grab the PenOp viewer
and check your document? The answer is no. He could, if he so
elects, just observe that the document contains something that
professes to be a signature and take it on face value to be
yours. That's always been our tradition with signatures. It is
very rare in commerce that signatures are tested for
genuineness.
It is common, of course, for one visually to examine her own
signature on a document, after-the-fact, to confirm for herself
that the document is hers and that she intended it to be the
final document (not a draft). While it is certainly possible
this informal examination would fail to detect a forgery, it is
very reliable in the context of other facts that corroborate the
authenticity of the document. PenOp supports such an informal
examination as it incorporates a graphic image of the signer's
signature into the MSWord document.
PenOp makes mimicry harder by requiring the image of the
signature physically to be drawn on a digital tablet within a
period of time that comports with the time you normally take to
sign. Tracing is not an option, as it used to be with paper and
ink. Another obstacle stands in the way of the forger. A signed
document does not exist in a vacuum. For the forger to achieve
his goals, he has to know a lot about the private facts and
circumstances between you and Boris -- he has to know in detail
what you two have been saying to each other, what industry jargon
you've been using, and what each expects of the other. He has to
intercept and carefully corrupt all the channels of feedback
between you so neither of you is ever tipped off that something
is amiss. If a crook e-mails Boris a contract falsely claiming
to be from you, he has to make sure Boris doesn't telephone you
to talk about it, or drop you a thank you card in the snail
mail. That's not easy.
To use public key crypto one must first go prove your identity
to a "certification authority," vow to keep the secrecy of a
private key (using passwords, smart cards, etc.) and thenceforth
immediately tell the authority if you ever lose the key. What's
more, a recipient like Boris has to coordinate with you and the
authority to confirm your key belongs to you and has not been
revoked. It's a hassle. Digital signatures are great for
making secure networks, but as symbols of commitment between
sentient people they fall short. They are too abstract. They
have no flourish, no flair, no style.
The special advantage of such an autograph is that its
purpose is clear. It is understood by both law and custom as a
metaphor for taking personal responsibility. Under both law and
business custom, a signature remains effective even if it might
theoretically be subject to forgery, repudiation or digital
trickery. The possibility of forgery might make proof in court
less than perfect, but commerce has always enjoyed less than
perfect proof. Extremely high degrees of proof are very
expensive to achieve. Some folks are tempted to make electronic
commerce more difficult than it needs to be. They say we need
radical new laws, we all need to learn new social rituals, and we
need to organize our lives in ways very different from our
established commercial customs.
PenOp reminds us of the collective wealth invested in those
customs and our surprising power to exploit them even in
cyberspace. When Boris gets your letter, signed with the aid of
PenOp, centuries of tradition, dating to J. Hancock and before,
arrive in its wake. From the signature Boris intuits far more
than can be gleaned just from the bare words in the letter. He
knows it's the flesh and blood you undertaking the commitment,
rather than merely your ThinkPad. Below appears the author's
signature, as captured and attached by PenOp to this document.
If you possess this document in its original electronic form,
available at http://www.penop.com, you can confirm the binding of
this signature to the document by using the viewer available at
the same address.
If you prefer not to trust software downloaded from a web
site, you may contact PenOp by telephone at +44-1373-452-755.
Do not change this document in any way. If you do, the binding
of the signature to the document cannot be confirmed. This
version of the document was created under MSWord 97; the
signature can be confirmed only if you are also using MSWord 97.
An MSWord 95 version is available at http://www.penop.com.
The Ritual of Commitment
A business negotiation is as much an emotional sport as a logical
one. The images and rituals informing the spectacle are as
important as the stated words. One ritual -- recognized in all
walks of life -- is the inscription of a handwritten autograph on
a document. It conveys trust, volition, understanding, resolve,
and conclusion, all in a single device. When John Hancock
inked his famous signature to the Declaration of Independence,
his intent was to all civilized people made manifest by the
ritual. That same ritual is carried into the digital world by
PenOp. PenOp is designed to apply signatures one-by-one. Each
time an MSWord document is signed, muscle and bone must pick up a
pen and write -- thus executing a physical ceremony. It is not a
dry, automated process. The PenOp software is not designed for
attaching a standardized signature file to documents.
Proof of Authenticity
Although ritual is its primary function, a signature can also
convey some proof of document authenticity. What kind of proof
would Boris have that your electronic letter, signed through
PenOp, really came from you and no one else? The proof would be
similar to, and in some ways even better than, the evidence he'd
have if he received paper from you. He'd have an image
purporting to be your autograph, which is bound by a
cryptographic routine to the words of the document.
Signature Forgery
What prevents someone from falsifying a document by forging your
autograph with PenOp? Practically speaking, the forger would
face several formidable challenges. Your PenOp signature cannot
just be clipped from one document and pasted to another. If it
is, the PenOp viewer will show that the document is not the one
to which the signature was originally attached. To forge your
autograph successfully, the forger must mimic it well.
No Keys Required
A PenOp signature should not be confused with a so-called
"digital signature," which is a complex process involving public
key cryptography. The best recognized public key software is
PGP. A digital signature shows that a certain key authenticated
a document. However, a digital signature does not necessarily
involve the action or volition of a warm, fleshly being. It is
simply the execution of a mathematical algorithm using a number
(key) stored in a computer somewhere. It is most commonly used
to authenticate machines on a network. It is a cold, mechanical
event, devoid of the emotional or social meaning associated with
handwritten signatures.
No Waiting for New Laws and Rituals
In principle, a PenOp signature can be just as legally effective
as any other kind of signature. Generally speaking a legal
signature is simply a symbol -- any kind of symbol -- that you
adopt for the purpose of taking responsibility for a document.
(See for instance Beatty vs First Exploration Fund, 25
B.C.L.R.2d 377 (1988), holding that an autograph on a fax is a
legal signature.) That standard is satisfied by an autograph
captured through PenOp.