I had this idea of one-way password manager which would not be dependent on any external software and would be easy to implement everywhere. To keep it more readable, this demo will trim all mutated strings to be 12 characters long.
There is a "seed" password and three "salt" passwords. The seed is supposed to be on plaintext and the salts are supposed to be secret, known only to the user.
Change your screen orientation to make the text more readable!
Seed
Salt 1
Salt 2
Salt 3
Short descriptions about the sequence
bread100
cat
dog
stonewall
Password and salts
First mutation:
3055d9cf285b
Seed password hashed with SHA-256
Mutation with salt 1:
3055d9cf285bcat
Salt 1 appended to mutated seed password
Second mutation:
bf92d8c57aee
Mutated and salted password hashed with SHA-256
Mutation with salt 2:
bf92d8c57aeedog
Salt 2 appended to mutated password
Third mutation:
568a17f1452b
Mutated and salted password hashed with SHA-256
Mutation with salt 3:
568a17f1452bstonewall
Salt 3 appended to mutated password
Final password
0f9e56d5efd9
Final password after last conversion
I think that the final password would be really hard to reverse engineer in a way that all three salts would be compromised. Additional features would be having just a single passphrase which would be split into seeds, having n amount of seeds and possibly adding logic for inserting special characters. Need for trimming mutated strings would not be present in the actual software; here I chose to do so just to keep the visualization a bit more readable.
The strength of this system is that you don't need to have any external application, just knowing how it works and having access to machine which can do hash calculations is enough. There is no fear of password database getting corrupted because the seed passwords can be on plaintext file and even in a physical form. User will still need a strong master passphrase similarly to the common password managers. That passphrase would be used for generating salts if the user prefers to not enter salts separatedly.