Juste besoin de cet execellent passage de Wikipedia (20200401)

RSA (Rivest–Shamir–Adleman) is one of the first public-key cryptosystems and is widely used for secure data transmission. In such a cryptosystem, the encryption key is public and distinct from the decryption key which is kept secret (private). In RSA, this asymmetry is based on the practical difficulty of factoring the product of two large prime numbers, the « factoring problem« . The acronym RSA is the initial letters of the surnames of Ron Rivest, Adi Shamir, and Leonard Adleman, who publicly described the algorithm in 1977. Clifford Cocks, an English mathematician working for the British intelligence agency Government Communications Headquarters (GCHQ), had developed an equivalent system in 1973, which was not declassified until 1997.^[1]

A user of RSA creates and then publishes a public key based on two large prime numbers, along with an auxiliary value. The prime numbers must be kept secret. Anyone can use the public key to encrypt a message, but only someone with knowledge of the prime numbers can decode the message.^[2] Breaking RSA encryption is known as the RSA problem. Whether it is as difficult as the factoring problem is an open question. There are no published methods to defeat the system if a large enough key is used.

RSA is a relatively slow algorithm, and because of this, it is less commonly used to directly encrypt user data. More often, RSA passes encrypted shared keys for symmetric key cryptography which in turn can perform bulk encryption-decryption operations at much higher speed.

A few basics about RSA (Rivest – Shamir – Adleman) cryptography encryption and decryption in java. Just for comparison with what we habitually do with openSSL without understanding any command 🙂

Check it online.

Reminder : RSA is an Asymmetric encryption technique that uses two different keys as public and private keys to perform the encryption and decryption. With RSA, you can encrypt sensitive information with a public key and a matching private key is used to decrypt the encrypted message. See details on RSA Cryptosystem on Wikipedia.

Public and private keys generation using KeyPairGenerator and asymmetric encryption and decryption with these keys.

https://github.com/bcgit

https://github.com/anishnath/crypto-tool

https://github.com/jaysridhar/java-stuff

How to Generate RSA Keys in Java

A l’occasion du forum des métier du numérique qui se tiendra à Saint-Malo le samedi 7 mars 2049, j’ai dépoussiéré ce vieil article d’il y a 3 ans : http://www.laurentmarot.fr/wordpress/?p=3737

D’ailleurs, il est grand temps que j’y aille 🙂

Forum IUT Saint Malo 2019

Bonne rigolade,

ca va parler un peu TLS, TDE, tout ça tout ça …

et puis ça augmente un peu la surface d’attaque de mon Honeypot

et puis ce sera un bon support pour mes TPs et mes tentatives d’acculturation au Ministère

MariaDB Encryption

https://www.digitalocean.com/community/tutorials/how-to-install-mariadb-on-debian-10

https://severalnines.com/blog/exploring-different-ways-encrypt-your-mariadb-data

et que ça marche malgré tous les warnings…

(sauf qu’au cours de la mise à jour la conf du répertoire d’uploads est pétée et doit être modifiée via interface web ou édition directe du fichier de conf).

Attention aux blagueur de StackOverflow qui conseillent le passage du répertoire en 777 🙂

From Beyrouth with Love

$ sudo add-apt-repository ppa:webupd8team/java
$ sudo apt-get update

Once PPA has been added and updated, now search for the packages with name oracle-java8 and install it as shown.

$ apt-cache search oracle-java8
$ sudo apt-get install oracle-java8-installer

If you have more than one Java installed on your system, you can install oracle-java8-set-default package to set Java 8 as default as shown.

$ sudo apt-get install oracle-java8-set-default

 # java -version
java version "1.8.0_161"
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)
root@zbook /usr/local/netbeans-8.2/bin
 # 

$ chmod +x netbeans-8.2-linux.sh 
$ ./netbeans-8.2-linux.sh

Magnifique …. Flottes de Combat 1914.  La Préface du Commandant de Balincourt : Priceless !

Chopé sur ebay à un prix raisonnable : 68 €

Le précédent achat remontait au 6 août 2017.

Il ne m’en manque plus beaucoup !

Ravi de terminer cette année 2017 sous d’aussi bon auspices pour 2018.
Le champ des possibles de la connerie humaine aura sans doute encore la possibilité de s’exprimer à travers la voix des cyber-experts-autoproclammés si l’on en juge des derniers évènements de l’actualité : Je lis ce matin dans la e-presse que ce petit rigolo black-faced de Grizou aurait démissionné du CNNUM suite aux reproches qui lui étaient adressés à son retour à 350 k€ en Mirage 2000 depuis Tokyo(Nouvelle Calédonie).
allez, keep on walking !