Cryptography 101 for Java developers by Michel Schudel
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- čas přidán 15. 05. 2019
- So you're logging in to your favorite crypto currency exchange over https using a username and password, executing some transactions, and you're not at all surprised that, security wise, everything's hunky dory...
The amount of cryptography to make all this happen is staggering. In order to appreciate and understand what goes on under the hood, as a developer, it's really important to dive into the key concepts of cryptography .
In this session, we discover what cryptography actually is, and will use the JCA (Java Cryptography API) en JCE (Java Cryptography Extensions) in the JDK to explain and demo key concepts such as:
Message digests (hashing)
Encryption, both symmetric and asymmetric
Digital signatures, both symmetric and asymmetric
Furthermore, we'll show how these concepts find their way into a variety of practical applications such as:
https and certificates
salted password checking
block chain technology
After this session, you'll have a better understanding of basic cryptography, its applications, and how to use the cryptography APIs in Java. - Věda a technologie
Cryptography at first place sounds so complex but Michel has made it so simple. Any novice would get a good sense of it just in 40 minutes. Thanks Michel.
Excelent! The most concise overview of securities API in Java
thanks!
Hi🇧🇷. This class is also an asmr. What a beautiful accent❣️
That was simply great.. In short time covered a lot with examples.. thumbs up!!!
Very nice Video, but one hint: The public key ist not shorter than the private key because it is an asymmetric method. It is shorter because the private key consists all informations/numbers and the public key only a part of it.
With OpenSSL you normally generate a (private) key. And with a second call you exctract the public key from this private key.
23:28 Diffie-Hellman Exchange (DHE) used out of the box is susceptible to man-in-the-middle attacks. Note that TLS can be configured to use DHE ciphers but, in these situations TLS will sign the DHE shared keys with RSA.
That was simply great. But I have 1 question:
When you explained about asymmetric cryptography, you said we encrypt with the private key and decrypt with the public key
I think it's only in digital signature, When we deal with the asymmetric key we should encrypt with the public key, and the receiver decrypts with the private key, no?
Thanks
Ya really, the talk was amazing... though i have worked on them but the way it was present with detail background knowledge was really nice...
I will store this video for my future references.
Can I request you to share the presentation also
Very informative and simple video to follow, thank you!
One quick question though which might sound a bit noob-ish: What's the point behind adding a "name: " before the string inside the parameter of Utils's functions? Whenever I try that out, it gives me errors.
EDIT: Apparently it's an IntelliJ feature, never used it before so makes sense why I was thrown off by it.
Thank you very much. The class was excellent.
I'd recommend the Computerphile video on the mathematics of Diffie-Hellman for anyone that's interested, it's actually quite elegant :)
Great presentation, thanks!
great talk, just amazing, thank u so much
Collision chances are almost square the age of universe= he says "Its takes quite a while, so don't worry" :D. Funny guy I must say! Enjoyed the talk as well the knowledge shared..
Great talk
Awesome exokanation man!!
Thank you for this great talk! It provides a nice quick overview of the Java classes to start with when using cryptography.
Shouldn't the RSA PUBLIC key be used in the example to ENCRYPT a message to provide confidentiality? The slide and code use the PRIVATE key for encryption and the PUBLIC key for decryption here?
It depends on what your want to do. For digital signatures, the sender encrypts using private key and the receiver decrypts using public key, because you want to be sure the sender is actually who he or she says eh/she is. When doing asymmetric encryption, you want to make sure that only the receipient can read your message. So, in that case, you encrupt using the receipient's public key, and he decrypts it using his private key.
asymmetric encryption is not really suited for large data because
1. Encrypted data is about 1,5 the size of the original data
2. Key of n bytes can only encrypt about n / 5 data in one turn
3. Symmetric encryption is a large magnitude of times (about 5000) faster than asymmetric encryption.
I know Im asking the wrong place but does any of you know of a method to get back into an instagram account..?
I somehow lost my password. I appreciate any assistance you can give me.
@Damon Reginald instablaster :)
@Kendall Joshua I really appreciate your reply. I found the site on google and Im trying it out atm.
I see it takes quite some time so I will get back to you later when my account password hopefully is recovered.
19.9 The decryption might have been happening in some other machine. How will it get the same 'key' object?
Good question! Symmetric key exchange can be done by using asymmetric encryption or DH-exchange. I hope I explained that a bit further in the session.
30:09 Sender encrypts using public key and receiver decrypts using private key. The slide is showing opposite. Can anybody verify this fact?
The slide says: sender encrypts using private key. Might have misspoken though, not checked yet... but the slide is the correct one.
The slide looks the wrong way round to me. Encrypt with a private key would lead to a digital signature.
Enigma was cracked by Polish mathematics, not by Turing FFS!
the world wants to know.
Exept Alice is blocked from hash
What if a bill of legislation has amended a hash and a block key. That is coded me as $ine & die dead and can't get id amd Evan if I did the hash will not let me inter it in and confirm in the s