Tag Info

Hot answers tagged

70

Firstly, often encryption is terminated at the perimeter by infrastructure which is dedicated to offloading SSL decryption. It makes it much easier to manage when you only have maintain a high degree of key security for a small (proportionally) group of servers which are dedicated to the role. The rest of your regular application servers can operate like ...


63

There are one-way functions in computer science (not mathematically proven, but you will be rich and famous if you prove otherwise). These functions are easy to solve one way but hard to reverse e.g. it is easy for you to compute 569 * 757 * 911 = 392397763 in a minute or two on a piece of paper. On the other if I gave you 392397763 and asked you to find the ...


33

Juggling is easy: you just throw the balls at the right time, so that you have a free hand when they fall. With one ball or two balls, this is trivial. With three, it is easy enough. With more balls, it (surprisingly) becomes harder. Even substantially harder. In all generality, "reversing" encryption done using an n-bit key is like juggling with 2n balls. ...


21

Your question is a little like this (with apologies to Tom Stoppard): "why can I stir the jam into my rice pudding, but not stir it out again?" Some mathematical operations are as easy to do backwards as forwards. For instance you can add 100 to a number as easily as subtracting 100. However, some are more difficult to reverse. For instance, if I take x and ...


5

The power in a certificate is NOT in the certificate. It is in the private key. When a server "uses a certificate", it really uses the private key; and the server shows the certificate (that contains only the public key) to the client. The certificate is a proof that a given public key belongs to a specifically named entity. For instance, the certificate ...


3

Max, the best tool ever created for thinking about cryptography is the Rubik's cube. If you presume a world where solving them is an unsolved problem, there are direct analogs for DiffieHellmanKeyExchange, RSA signing, RSA encryption, etc. You can play tricks with writing down moves and performing them on cubes and exchanging them; and the group theory ...


3

The two keys you show are encoded differently - obviously, the first is base64 encoded, and the second is hexadecimal encoding. You would need to determine the formats used and their encoding to determine how to reconcile the two. And in both cases it's a packed structure, not just raw key data but discrete bits of data like key type, exponent, and ...


2

From what I'm understand, what you're trying to do is to verify, after you are sure that the page arrived from the network untouched (since it's TLS), that it has not be modified by any client-side malware. Since it's a client-side malware, it's safe to presume it can change anything he wants on the client side, after the session is decrypted from the TLS ...


2

The structure is all wrong. If Google uses this intermediate cert only for signing Google-owned domains (which I think is the case) they can't do it with a restricted path certificate, because they need to sign google.com and google.co.uk and gmail.com and even com.google now that they own that TLD. In my opinion, the PKI was poorly designed to begin with, ...


2

I think there is an additional problem/challenge with your scheme: Beside the problem of having the key pairs generated by the server, this scheme also allows for a man in the middle attack: A asks for the key of B, server answers with his own key C. Now the server can decrypt, read and encrypt again for B and send the new ciphertext to B. Neither A nor B ...


2

Owner and Signature Trust Signature trust means a user puts trust into the identity of another user. If Alice signs (or certifies, which is the term I will use from now on for signing other's keys) Bob's key, she declares (following whatever rules) she puts trust in his identity. These certifications are usually publicly available on the key servers. You ...


2

What you need to do is read up on Public-Key Cryptography. The short answer is it is based on an algorithm that allows one key to encrypt and the other key to do the decryption, which is why you cannot work backwards. That is a simplified explanation of what is happening, if you want to get to the heart of the issue you can look at sources such as the ...


1

Diti is almost right about the historical context, but the real historical reason is in the part he/she omitted. For quite some time, gpg used DSA keys by default, which can only be used for signing, and then had to attach an elGamal subkey (which can be used for encryption only) to get a fully functional key. For RSA, that isn't necessary, but it was kept ...


1

I found a solution as I was looking for; http://blog.engelke.com/2015/03/03/creating-x-509-certificates-with-web-crypto-and-pkijs/ But I'll try pem modulus at first. Because it works on back-end and seems more simple.


1

It's possible that this CA certificate is linked to GeoTrust's root certificate by way of Geotrust's 'GeoRoot' service, which "Allows Organizations with Their Own Certificate Authority (CA) to Chain to GeoTrust's Ubiquitous Public Root ". See ...



Only top voted, non community-wiki answers of a minimum length are eligible