Here are links to a number of live-to-web cryptographic toy engines for you to experiment with. I have attempted to include a working engine, ALGORITHM (in Pseudocode) and a link that lets you examine the PHP code I wrote to implement each algorithm. Comments/suggestions are welcome.

Related encryption examples

- ISO Checksum - Try it here
- Reverse Cipher (is this even encryption?) - Try it here
- Conversion Centre (quick and dirty number info masher) - Try it here

Where the same "key" is used to encrypt and decrypt messages - security of the key is the make/break of these ciphers.

stolen from https://www.ssl2buy.com/wiki/symmetric-vs-asymmetric-encryption-what-are-differences

- Caesar Cipher (a simple alphabtic transposition cipher) - Try it here
- Transposition/Block Cipher (a key-driven grid based cipher) - Try it here
- Vignere Cipher (a more complex polyalphabetic cipher) - Try it here
- One-time Pad Cipher (the "perfect" cipher?) - Try it here
- example Try it here
- example Try it here

Where there are different keys for encryption/decryption ("public"/"private"). This way "anyone" can encrypt a message using the public key, but only those with the secret key can decrypt it.

stolen from https://www.ssl2buy.com/wiki/symmetric-vs-asymmetric-encryption-what-are-differences

- example Try it here
- example Try it here