# What constitutes an 'electronic signature'?

**URL:** <https://boards.straightdope.com/t/what-constitutes-an-electronic-signature/211425>\
**Category:** Factual Questions\
**Created:** [November 4, 2003, 9:50pm UTC](https://boards.straightdope.com/t/what-constitutes-an-electronic-signature/211425 "2003-11-04T21:50:38Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![JohnBarleycorn](https://avatars.discourse-cdn.com/v4/letter/j/e19adc/32.png) [@JohnBarleycorn](https://boards.straightdope.com/u/JohnBarleycorn)\
**Post date:** [November 4, 2003, 9:50pm UTC](https://boards.straightdope.com/t/what-constitutes-an-electronic-signature/211425/1 "2003-11-04T21:50:38Z")

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When I signed up for an MSN passport it says this:

> [@](#):
>
> .NET Passport Terms of Use  
> When I click I Agree, I attach my _electronic signature_ to and agree to the Terms of Use for Hotmail and for the .NET Passport Services; I also accept the MSN Privacy Statement and the .NET Passport Privacy Statement. I understand that, by registering for an MSN Hotmail account, I agree to receive targeted advertisements from MSN. I also understand that if I do not agree to these terms of use, I should click Cancel, discontinue my registration, and refrain from using the Hotmail and .NET Passport Services.

What exactly are they asking me to agree to? I have no idea what ‘electronic signature’ is.

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**Author:** ![Punoqllads](https://avatars.discourse-cdn.com/v4/letter/p/d2c977/32.png) [@Punoqllads](https://boards.straightdope.com/u/Punoqllads)\
**Post date:** [November 4, 2003, 9:54pm UTC](https://boards.straightdope.com/t/what-constitutes-an-electronic-signature/211425/2 "2003-11-04T21:54:00Z")

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An electronic signature is a method of taking a given message, along with a user’s private cryptographic key, and generating a digest code that verifies that the message that was received is exactly the same as what the person who signed it sent.

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**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\
**Post date:** [November 4, 2003, 10:47pm UTC](https://boards.straightdope.com/t/what-constitutes-an-electronic-signature/211425/3 "2003-11-04T22:47:57Z")

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Think of it as a “tamper-evident seal” on a message.

It’s hard to prevent a message from being altered after it is sent. But it’s relatively easy to give a recipient a means to tell whether or not the message arrived intact.

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**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\
**Post date:** [November 5, 2003, 3:45am UTC](https://boards.straightdope.com/t/what-constitutes-an-electronic-signature/211425/4 "2003-11-05T03:45:23Z")

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But how does MSN know his public key? Did it create one for him when he signed up for this Passport thingy?

I read this same warning about 1.5 years ago when I got a new computer. It came with McAffee Virus Scan, which would give you free updates if you registered with them, but you couldn’t register with them without an MS Passport. I read their little agreement and decided I’d rather have outdated virus definitions.