Optimus Prime RSA

This program can find two prime numbers from a set of given prime numbers, from which a private key can be generated that matches a given public key. Afterwards, the private key can be used to decrypt a cipher.

The special feature is that this is done in a distributed manner. This means that the program can run on several hosts simultaneously to find a solution.

Pre-start information

• The same program is executed on all hosts.
• Within the process, a distinction is made between masters and slaves.
  • The master is the process that tells the other processes (slaves) what their task is. In addition, information about the master is distributed, which is needed should a slave take over the role of the master in the future.
  • Slaves provide workers that process the task assigned by the master. If a master fails, a slave becomes the master.
• The process that is the master also hosts a slave unless otherwise specified.
• To give a task into the distributed system, there is a client software.

Starting a server

The master must be started first. After that, slaves and clients can connect.

Requirements:

• On each server, the firewall is opened for port 2504 and 2505 or as specified in --intra-port and --client-port for incoming TCP traffic.

In the following, the following preconditions are assumed:

• The ip of the host that the master is running on is 192.168.42.100
• The ip of the host that a slave is running on is 192.168.42.200
• Master and Slaves are on the same network: 192.168.42.0/24

Starting the master

No arguments are required to start a master, since the default master address ist localhost.

The following arguments are recommended to use:

• --master-address: Use a non-localhost address, that is used by a NIC on the host

java -jar optimus-prime-rsa-v1.0-server.jar --master-address 192.168.42.100

Starting a slave

The following arguments are required:

• --master-address: Specify the master address. Hint: This has to be an address not associated to any NIC on the host.

java -jar optimus-prime-rsa-v1.0-server.jar --master-address 192.168.42.100

Command line arguments

Key	Description	Master-Only	Default	Required
--master-address	defines the ip-address of the current master	false	localhost	false
--master-checks-per-slice-per-worker	defines the number of checks per slice per worker	true	150000	false
--intra-port	defines the TCP port to use for communication between server	false	2504	false
--client-port	defines the TCP port to use for communication with the client	false	2505	false
--workers	defines the number of the threads that are used to crack the key	false	<threads> - 1	false
--max-slaves	defines how many slaves can connect to the master	true	1000	false

Starting the client

The master must be started first. After that a client can connect.

In the following, the following preconditions are assumed:

• The master is running
• The ip of the host that the master is running on is 192.168.42.100
• Client and master are on the same network: 192.168.42.0/24

The following arguments are required:

• --ip-address: Specify an ip-address of a server of the distributed system
• --pub-key-rsa: Specify the public key as BigInt
• --cipher: The cipher to crack

The following arguments are recommended to use:

• --primes: Specify the primes list to use

java -jar optimus-prime-rsa-v1.0-client.jar \
    --ip-address 192.168.42.100 \
    --pub-key-rsa 237023640130486964288372516117459992717 \
    --cipher a9fc180908ad5f60556fa42b3f76e30f48bcddfad906f312b6ca429f25cebbd0 \
    --primes 10000

Command line arguments

Key	Description	Default	Required
--ip-address	ip-address of a random server		true
--port	defines the TCP port to use for communication with the system	2505	false
--pub-key-rsa	defines the public-key to crack		true
--cipher	defines encrypted payload to decrypt		true
--primes	defines the prime list to use (100, 1000, 10000, 100000 or custom file)	100	false

Hints

• set --workers to 0 on the master to use it for communication only.