contract-law binding
How to prevent the problem of a document changing its content after you signed it
<p>I just read <a href="https://www.quora.com/Can-NDAs-non-disclosure-agreements-be-signed-through-an-online-form-Are-there-any-legal-implications-with-an-online-form" rel="nofollow noreferrer">this</a>:</p>

<blockquote>
  <p>The problem is that if there is a dispute over what was actually in the NDA later on, its going to be extremely difficult to establish what the NDA said.  I'd refuse to sign an online NDA out of fear that some years from now, I'd be presented with "you signed this document" which looks nothing like the document I thought I signed.</p>
</blockquote>

<p>I think this is applicable to both online and hardcopy documents in the same way. For hardcopy, someone with enough sophistication could just either copy your signature, or graft it from one document to another. Likewise, for electronic media, you could easily just paste their electronic signature onto a different document, since it's just bits of 1's and 0's that the document is saved in the database or cloud with, so it's easily changed.</p>

<p>I'm wondering how you can prevent these problems. If you are the one creating the document to be signed, wondering what must need to be done so that if you were in court the document would be considered valid, the content considered the original content and valid, and the signature considered valid. If you give a copy of the document to the person signing it, then they could use it to reference the original. But if they lose it, then they lose the protection. Also, they could just throw it away and say that they never got a copy, and say that you changed the original contract. I'm not sure how one would protect against this sort of stuff, what needs to be done on the document creator's part to maintain "legal validity" or "legal soundness". Seems like documenting the process somehow might help, but I can see loopholes there as well. Hoping one could outline/clarify what should be done here.</p>

<p>The USPS and other postal services have created a service called <a href="https://en.wikipedia.org/wiki/Digital_Postmarks" rel="nofollow noreferrer">Digital Postmarks</a> or EPCM (Electronic Postal Certification Mark) to address exactly this problem.</p>

<p>Basically you can upload any document that you want to be "unalterable and time stamped". The service computes a hash (a number that will change if the contents change), and store the time stamp and the hash on a secure server.</p>

<p>If, at some time in the future, you want to confirm the authenticity of the document, you can upload another copy - the fact that it produces the same hash proves it's not been tampered with.</p>

<p>One common practice is to sign every page on a hard copy and to initial every other page of a hard copy, usually with blue colored ink on a black and white original, and to maintain a copy of the original as authoritative.</p>
<p>Most electronic digital signature systems have some sort of authentication protocol.</p>
<p>One can also maintain a copy of what you signed in some way that can be authenticated (e.g. with metadata).</p>
<p>Certainly, a sophisticated party can find a way to fabricate or forge almost everything, but this doesn't come up very often because most merchants engaging in contracts with lawyer drafted written documents almost never, as a matter of empirical reality, actually do that, and because the lawyers acting as intermediaries have ethical obligations independent of and superseding their duties to their clients not to engage in that kind of fraud and not to submit false evidence. Also, when someone is discovered to have done something like that the implications are often not limited to that transaction and can instead also result in criminal charges and/or loss of professional licensure and punitive damages.</p>
<p>Has there ever been a case where a lawyer and a business client have conspired to engage in outright forgery? Certainly. But this doesn't happen often and one takes enough precautions to make it unlikely and then lives with the risk. At some point one has to balance the risk of being defrauded against the benefit of doing business. In most situations, there is a customary way of documenting transactions and that is considered &quot;good enough&quot; even though it isn't perfect and most of the time it works.</p>
<p>The risk is largely a function of who you are dealing with.</p>
<p>For example, most transfers of commodities on commodity exchanges in the U.S. and publicly held securities listed on securities exchanges other than the NASDAQ aren't documented by written contracts at all, and instead are conducted by oral agreements documented in writing in the personal business notes of the parties.</p>
<p>Similarly, most decisions of the boards of publicly held corporations and governmental entities are made orally and then documented by a secretary of the meeting in minutes, rather than in documents executed by the decision makers. In each of these contexts, there is a sufficient basis for trust that signed documentation is not needed, in part, because the people interacting constantly interact with other other in transactions large and small, and no one will continue to do business with someone who proves untrustworthy.</p>
<p>The risk is much higher when a transaction is for high stakes between people who don't deal with each other personally very often and aren't working through intermediaries who do deal with each other very often (working through intermediaries who are established and regularly deal with each other and have an economic interest in being able to continue to do so is one way to mitigate the risk).</p>
<p>When the risk is high and the stakes are particularly great, one can not only use an original wet ink copy but entrust the original for safekeeping to a trustworthy third-party. Sometimes witnesses, notarizations, or &quot;guaranteed signatures&quot; (a private sector analog to a notarization in which the risk of fraud is insured by the guarantor of the signature) are also common tools to further reduce this risk.</p>
<p>In Continental Europe and many other &quot;civil law&quot; countries that don't follow the English Common Law legal system, notaries serve the role of third-party signature verifier and third-party custodian of important contracts in a far greater share of significant, legal professional drafted contracts and legal instruments than in the U.S. and other common law jurisdictions.</p>

<p>I quote <a href="https://ak-law.ca/contract-signing/#8" rel="nofollow noreferrer">https://ak-law.ca/contract-signing/#8</a>.</p>
<blockquote>
<p>In some legal instances, when the law requires, each page of a document or contract will need to be initialed.</p>
<p>For example, under article 728 of the Civil Code of Quebec, when a will is written by a third person or electronically, the testator and the witnesses must <a href="http://legisquebec.gouv.qc.ca/en/showdoc/cs/ccq-1991" rel="nofollow noreferrer">initial or sign each page</a> of the will.</p>
</blockquote>
<blockquote>
<p><a href="https://www.legisquebec.gouv.qc.ca/en/document/cs/ccq-1991#se:728" rel="nofollow noreferrer">728.</a> Where the will is written by a third person or by technical means, the testator and the witnesses initial or sign each page of the act which does not bear their signature.
The absence of initials or a signature on each page does not prevent a will made before a notary that is not valid as a notarial will from being valid as a will made in the presence of witnesses, if the other formalities are observed.</p>
<p>1991, c. 64, a. 728; I.N. 2014-05-01; I.N. 2015-11-01; 2016, c. 4, s. 99.</p>
</blockquote>
