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1

Note, there is no legitimate reason to hide the algorithm used if you use a suitably strong passphrase/key. If you are really concerned, you could open the encrypted file in a hex editor and change the fourth byte of the symmetrically encrypted ASCII armored file. E.g., the first four bytes of an symmetric encrypted file are: 8C 0D 04 09 with the ...


2

It looks like the passphrase which was used to encrypt the message with is encrypted with AES256. The algorithm used to encrypt the message is self is not known until the encrypted session key packet is decrypted. This is what pgpdump shows: Old: Symmetric-Key Encrypted Session Key Packet(tag 3)(13 bytes) New version(4) Sym alg - AES with 256-bit key(sym ...


0

In a – more of theoretical nature – attack described by Jallad, Katz, Schneier in 2002, the MDC would prevent the attack, no matter whether an additional signature is applied or not. The Attack The attack boils down to the fact that encrypted data tampered with will not necessarily fail during decryption (in a sense that the implementation shows a ...


0

As rightly pointed out, the private key is not involved in encrypting, the only thing involved in the scenario from the question is the public key, and obviously everyone already has the public key, so it really doesn't matter if the security agency intercepts the public anc encrypted messages or not, it can encrypt whatever it wants with the public key. ...


1

The MDC spec allows you to request a specific hash. The default, MD5, is now considered deprecated. All MDC implementations are required to support SHA-1. You can also request SHA256 or SHA512. Assuming you have a sufficiently secure hash in use with MDC, there's no reason to attach another.


0

SSL is already included in most libraries nativelly, so the difference between a plain text webservice and the SSL version is negligible in terms of development on both sides. If the client makes use of persistent connections or reuses the SSL session, the negotiation between client and server is even lighter and faster. The authentication proccess is easier ...


3

PGP/GPG is generally not used for web services. It relies on anyone communicating to have the public key of who they're communicating with. In web services this generally isn't guaranteed. So depending on the type of service you're providing this might not be ideal. If you're trying to only provide services to a select group of people then you'd have ...


1

SSL will be faster than SOAP+PGP. Cryptographically, both SSL and PGP are hybrid systems which use public key cryptography to protect symmetric session keys. In practice, SSL has been tuned on the client and server side to do what it's doing quickly, PGP hasn't been optimized for this case. And you'll have to figure out your key distribution and trust ...


1

In general when addressing encryption as long as two different session keys are used, and something other than block cipher mode ECB is used, very rarely will patterns be seen in the encryption. GPG supports compression which would remove most patterns in the data first. It then uses one time randomly generated session keys to symmetrically encrypt the ...


1

Update: I retract that. PGP uses symmetric encryption for the payload. So the real reason that both messages are different, is that each e-mail is encrypted using a different symmetric key (session key), which is in turn asymmetrically encrypted. Without having checked that, I think it is safe to assume that GnuPG uses padding with RSA (OAEP probably). This ...


0

After reading about this problem and finding out about Bicoin timestamping, I came up with a relatively simple way to make yourself a way to prove that you are the owner of a pseudonymous ID using a PGP key and a Bitcoin address in your ownership. This system relies on the fact that in order to unlock these two things you require a secret which, in ...


4

This is called hybrid encryption. It is needed for the following reasons: Asymmetric encryption algorithms like RSA or ElGamal are very limited in the size of messages that they can process. If you use a 2048-bit RSA key, the maximum size of the data that you are going to encrypt is 245 bytes, no more. There is no currently known, clear, fully specified ...


8

There are two reasons: RSA and other assymetric algorithms are very slow. It is faster to encrypt a small key using the assymetric algorithm, and encrypt the message using that key with a faster and symmetric cipher. In its default setup, RSA is insecure. It needs a padding scheme to get full security. This "random key" method is part of such a padding ...


0

You seem to be begging the question here. I would no more try to convince my mother that she needs to use encryption than I would try to convince her she needs to use a chainsaw or an oxyacetylene torch when she shows no interest in those things. How does littering the internet with abandoned and poorly secured private key files, and littering the public ...


1

You need encryption if you don't want your sexts and other "naughty" messages becoming water cooler topics at the NSA's HQ. Not a very detailed answer, but in my opinion that's the most important problem for someone that has nothing to hide (about the other risks mentioned in the other answers - how many times did your neighbor attack your WLAN and tried to ...


1

Do you want your bank details stolen and all the money in your account removed? No? You need encryption. Do you want anyone to alter your emails so they say something rude/incriminatory/racist? No? You need encryption. Do you want people to use your network or PC to download or store illegal materials? No? You need encryption. Do you want crooks to hijack ...


2

I think the others covered signing already pretty well, so I'll present my thoughts on encryption. Possible Reasons for encryption for everyday people They would (or should) want it because pretty much nobody has nothing to hide. It doesn't have to be anything illegal. If people really think about it, they can come up with an embarrassing secret they do ...


1

I think everyone should run their own mail servers (non-locally, of course). However, barring that (and the security risks from faulty software), it's just a good idea to have all information that is on a stranger/untrusted party's computer be encrypted. That information is stored for a long time (with gmail, forever), so 10+ years in the future, things may ...


1

Even a simple user doesn't think that he needs encryption , but he actually does because sometimes and i say "sometime" , those simple messages can show the psychology of a person which can leads to exploiting them in anyway you want . also as stated above encryption validates the identity of the person you're talking to .


1

Encryption can also help validate the identity of a conversation partner. This can prevent fraud such as phishing. A simple example of this is giving your child a safeword, or instructing your employees not to heed any instructions coming from an unsigned or improperly signed source. Thus your child will not be abducted by an extended friend of the ...


33

Removing a Local-Only Signature If the signature is still only kept locally (either by never sending it to anybody or the key servers, or by even having performed an lsign which creates signatures that cannot be uploaded), you can actually delete it by running gpg --edit-key [keyid] [select a uid] delsig [go through the assistant for deleting signatures] ...


10

You can't unsign, but you can revoke your signature on their key. Once someone has synced both the original signature and the revocation, their UI should show both and will no longer use the signature in trust calculations. To do this with GnuPG: gpg --edit-key KEYID revsig <Supply a reason> gpg --send-key KEYID # Upload key to keyserver, or gpg ...



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