CTFs

Address Generation

https://github.com/MyEtherWallet/VanityEth

Generate multiple addresses
Supports Multi-core processors
vanity contract address
log to file
checksum based vanity address

Blockchain Layers

Cryptography

Solidity

OP-Codes

https://www.ethervm.io/

https://www.evm.codes/?fork=shanghai

There is a variety of OP Codes available

Stack-manipulating opcodes (POP, PUSH, DUP, SWAP)