How to Stop Man in the Middle Attacks Part 2

Continuing my explanation of how encrypted communications work, here’s how public/private key cryptography works: First Alice creates a special file called a “private key” using a public/private key algorithm (like this one) and then uses that file to generate a “public key”.

She gives the public key away to anyone she can and keeps the private key private (sort of like a password except that it’s too big to memorize and is therefore stored in a file). She can use the private key to encrypt a message in such a way that only the public key can decrypt it.

This is pretty useless for encryption since anyone who has the PUBLIC key can decrypt it; however it does solve our problem of detecting someone modifying our message.

Mallory can’t replace our message because if she does she will have to encrypt it with Alice’s private key (which she does not have), and Bob will know it wasn’t encrypted with Alice’s private key because it does not decrypt correctly. She also can’t modify Alice’s messages because that would logically mean making an entirely new message. This is called a “digital signature”.

Now Alice and Bob can exchange keys without Mallory being able to eavesdrop on them so long as Alice encrypts the number that she sends with her private key. Bob does not need to have a private key as he can actually encrypt the number he sends using Alice’s public key in such a way that only Alice’s private key can be used to decrypt it.

They can now communicate with each other safe from both Mallory and Eve; however this method requires “prior secrets”. In other words this method requires that Bob already have Alice’s public key. Alice can’t simply transmit her public key to Bob over the Internet because then Mallory could just replace it with her own. She also can’t sign her public key with her private key (creating a “self-signed certificate”) because Bob doesn’t have Alice’s public key to verify it with.

This is where “trusted third parties” come from.

12 thoughts on “How to Stop Man in the Middle Attacks Part 2

  1. Hello There. I found your blog using msn. This is a very well written article.

    I’ll make sure to bookmark it and come back to read more of your useful info.

    Thanks for the post. I’ll definitely return.

  2. Pingback: 他妈的谷歌
  3. Some gamers intentionally depart just a few elixir gatherers and mines outside
    the partitions so other players can farm them without destroying the whole lot
    they’ve, though it is often sensible to go away decrease-precedence buildings like those outdoors your partitions so you can make sure the necessary stuff is best-protected
    with overlapping fields of fire somewhat than overlaying a wider
    space.

  4. They can do flexible shopping, which gives them a different taste and
    flavor altogether. He is a graduate of the Bronx
    High School Of Science. People are more than likely to buy
    a piece of artwork from a well-known artist (even if it.
    If you’re willing to spend a considerable amount of money, you can purchase brand name
    one that may get you noticed every time you wear them.
    If you want your look to be casual and fun, try wearing tight-fitting neon-coloured tights under your dress.
    These posts are released at a minimum of once per day depending on the social media site.
    If you travel by train, check their guidelines to determine an appropriate
    size.

  5. Pingback: mobil porn
  6. Pingback: mobil porn
  7. Pingback: porno
  8. There was one more recommendation that is most controversial.
    This is where originated the concept of exhilarating headlines being mentioned on
    the first page of a newspaper. Because of the internet and cell phones, news
    stories are delivered even faster than ever before.

  9. I don’t know whether it’s just me or if perhaps everyone else encountering issues with your blog.
    It appears like some of the text on your posts are running off the screen. Can someone
    else please comment and let me know if this is happening to
    them too? This could be a issue with my web browser because I’ve had
    this happen previously. Cheers

  10. Pingback: 他妈的谷歌
  11. Hello! Someone in my Myspace group shared this website with us so I came to look it over.
    I’m definitely enjoying the information. I’m bookmarking and will be tweeting this to my
    followers! Superb blog and outstanding design and style.

  12. Woah! I’m really loving the template/theme of this site.
    It’s simple, yet effective. A lot of times it’s hard to get that
    “perfect balance” between usability and visual appeal. I must say that you’ve done a
    superb job with this. Also, the blog loads super quick
    for me on Opera. Superb Blog!

Leave a Reply

Your email address will not be published. Required fields are marked *

Please prove that you are not a spam-bot *