Hot answers tagged

148

TL;DR: No, Telegram is not secure. I'd like to ignore the comparison to WhatsApp because WhatsApp does not advertise itself as a "secure" messaging option. I'd like to instead focus on whether Telegram is secure. Telegram's security is built around their home spun MTProto protocol. We all know that the first rule of Cryptography is Don't Roll Your Own ...


56

As of May 2016, this answer is out of date. Whatsapp rolled out E2E encryption. I will compare Telegram and Whatsapp in 3 aspects: Storage of messages, encryption, and zero-day vurnerabitiles. In fact I will be comparing 3 technologies: Telegram's regular chats (which I will refer to as "normal chats", or simply "chats"), Telegram's secret chats, and ...


30

Many of the news were just sensational news, not actual. There have been reports surfacing after this that security agencies monitor xbox and playstation communications. It came up as a playstation was found in one of the Paris attackers flats. It was baseless and been debunked quickly (https://motherboard.vice.com/read/how-the-baseless-terrorists-...


22

Some random thoughts... Pidgin provides a lot of security features and support a lot of sec protocols and it provides strong encryption. It is Free and Open Source. Features include Automatically creates a public/private key pair for you upon loading the plugin. Automatically transmits your public key to other users. Supports 512 - 4096 bit keys. Saves ...


19

At the annual IEEE Security & Privacy conference in 2011, White et al. presented some very involved research on reconstructing encrypted VoIP sessions. The image below shows the overall architecture of the authors' approach. Although it works only for variable bitrate codecs (most common VoIP codecs are constant bitrate, e.g. G.711), the results are ...


14

This is incomplete. But hopefully of some use. http://imfreedom.org/wiki/IMessage and https://github.com/meeee/pushproxy (especially the docs section) have done some reverse engineering of apple's proprietary protocol. Seems that every apple device has a SSL/TLS client-side cert for authentication that setup to be known to apple's push server. This is ...


14

As the Telegram FAQ mentions, there is a 'secret chat' option that does not store chats on their servers. As for the underlying question of, "does storing chats lower their security?" then that is something to consider. Chats being stored on the server does mean that copies can be made on the server for decryption later. This increases the exposure of the ...


12

Questions I would ask myself before using skype for sending sensitive information: Is the encryption truly end-user to end-user or is the data only encrypted between the user and Skype (thereby potentially giving Skype access)? How are IM logs managed? Can you be sure that you have 'deleted' the password from the log? Even if logs are not being stored to ...


12

In general yes, there is ways of doing this, as a quick google search would've been able to tell you. When ever you call, write or send a file to a person on skype you make direct contact with the persons IP/ISP IP, and that you are of course able to track. A simple way to do it in windows is using netstat -n while in a call, and look for the port you know ...


12

Correct: The Web-Client is establishing a secure connection to the phone. The messages you send through WhatsApp Web are encrypted by the WebClient, decrypted by the phone, then re-encrypted to fit the end-to-end scheme and then sent to the recipient. Same thing the other way around. I dont know details about the protocol, but this is what i suspect (or how ...


9

Public key cryptography can, in this case, be used to facilitate setting up a secure channel in which to transmit a symmetric key. Once the secure channel has been set up, it is not necessary to continue to encrypt and decrypt using the public/private keys. Instead, generate a symmetric key and use that to encrypt the traffic. You only have to distribute ...


9

This question is hard to answer without knowledge of who and what you wish to be secure from. Does "practically secure" mean you are unlikely to be eavesdropped? If it does, then Skype (for example) is a good choice, due to it's encryption. Which country are you in? Some countries have 'lawful intercept' laws which require that authorised law enforcement ...


9

In the Skype protocol there are also "proxy nodes" that relay traffic for you. Every Skype client can in fact become such a proxy node if the network reachability is good, especially in regard to firewall conditions. So you can't be sure if the peer IP address you are seeing is the one of your call partner or of a random proxy node. In the latter case you ...


8

"A password" is not enough information to determine how it needs to be protected. What resources does the password grant access to, and what level of access? Skype uses reasonably strong encryption on voice communication--we think. It's closed-source, so what we know comes from documentation and protocol reversing. You can't look at their source code to ...


8

There have been several suggestions that skype is indeed backdoored and evesdroppable. If your concerned about it because Microsoft is now the owner, there are plenty of other alternatives to Skype which I would suggest as the easiest and cleanest solution (besides, if MS is your competitor, why would you buy their services). Some of the alternatives like ...


7

Avaya's quick two-page checklist is broadly vendor neutral. Key first steps include: H.235.5 for H.323 signaling encryption SRTP* for H.323 / SIP media encryption (10 bytes overhead per packet) Standalone AES encryption can also be used for H.323 media encryption TLS for SIP signaling encryption SRTP for voicemail interaction TLS for adjunct ...


7

Let me try to sum up what the landscape of end-to-end encrypted messaging protocols for group chat looks like: Protocols like PGP have been around for some time and offer "group messaging" by simply encrypting the content with a randomly generated symmetric key and then encrypting that key asymmetrically with the public keys of each of the recipients. ...


6

As far as I understand, SMP does not protect against MitM per se. The paper's authors clearly state, Suppose that Alice and Bob are chatting online using OTR and decide to run the SMP, but have not previously selected a secret and possess no channel more secure than their current conversation. They can still select an appropriate secret in this ...


6

Besides the protocol issues, the app itself is not very secure. In February 2015, Zimperium published a detailed analysis of Telegram's local vulnerability, allowing the attacker to get full access to plain text messages. Basically, even if the protocol was secure, the application itself isn't, becoming the weak link in secure communication. According to ...


6

I think your group is in fact a so-called Super Group. Super Groups work a little differently than normal groups and the one-check/two-check system doesn't apply here. All messages get double checks instantly when received by the server. (That's a feature.) The creator of your original group has clicked the 'upgrade to supergroup' button at some point, ...


5

Here is what I know: AIM/.Mac/ICQ (Oscar): supports optional SSL for client-server encryption. Jabber/GoogleTalk (XMPP): supports optional SSL for client-server encryption. Supports PGP. On these and other networks (MSN, Yahoo, GaduGadu), you should be able to use OTR messaging which provides simple, easy to use encryption. Both parties must have the OTR ...


5

That Skype might be backdoored has long been a concern. See link below. https://ultraparanoid.wordpress.com/2007/06/19/why-skype-is-evil/ I also noted in a past review I did that the official, independent crypto review and the description gained by a reverse engineering team differed significantly. The latter had design flaws and working exploits. Also, ...


5

This depends on model you use for group chat: Peer-to-peer: You need to encrypt each message with the recipient's puiblic key and send it to each user separately, and create the "illusion" of a group chat. This will prevent new group joiners to see previous messages. Client-Server: You upload the messages "signed" to the server, and encrypt them to each ...


5

The objective of Diffie-Helmann (I guess they authenticate DH somehow) is only key distribution. The objective of MTProto is encryption. Diffie-Helmann feeds MTProto with keys lets say. It is in a higher level. Although MTProto is 'broken', secure key establishment still takes place. So DH effectively does not fail in its purpose (key distribution). ...


5

The flaw with iMessage reference aboved was that it was: A) Vulnerable to a brute force attack This was because of a bug discovered by the researchers that allowed a man-in-the-middle-attack to be setup, due to: Strict certificate pinning was not used until iOS 9 -- so an attacker could create an impostor certificate and hack DNS on their local ...


4

http://www.cypherpunks.ca/otr/ is a plugin for several clients. I've used it with Adium on OS X and with Pidgin on Windows. It also works with Pidgin on Linux. The greatest part of this is that it is protocol independent -- you can use it to secure conversations on Google Chat, Jabber, AIM, etc.


4

Is it possible for the ISP or any middle point? If you meant is it possible for the ISP/middle point to decipher/decode/snoop on your chat, then the answer is yes. For unencrypted voice transports, all you need is a wireshark plugin to reconstruct the chat out of the pcap files. Check out http://www.panoramisk.com/151/analyzing-voip-with-wireshark/en/ ...


4

The most efficient way is to have client's exchange their RSA public keys and then generate random "session keys" to use for conversations with each other. This avoids multiple encryption and doesn't require the server to be able to decrypt the data. So if Jack is going to talk to Jill and Seth, Jack generates a random encryption key to use to talk to Jill ...


4

You're confusing two different companies and products: WhisperText LLC which develops the Whisper App They're the geolocating datasharing company that drew the criticism you linked. Open Whisper Systems which develops TextSecure, RedPhone, Signal These are various end to end encrypted products. I have seen no reason to distrust them. But obviously even ...



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