Analyse probability of linking input to output through a ring, or multiple rings

[HarryR]

For example:

• Alice Deposits into a Ring of size 4 (A)
• All inputs are Withdrawn into 4 other Rings (B, C, D & E), each of size 4.
• This requires 12 additional Deposits.

When a Withdrawal is made from A, the probability that it is Alice is 1/4.

When a Withdrawal is made from B, C, D or E the probability that it is Alice is at least 1/16.

For more information, see:

• https://eprint.iacr.org/2017/338.pdf
• [Discussion] Raising the mandatory ringsize in the v6 hardfork, September 2017 monero-project/monero#1673 (comment)
• https://lab.getmonero.org/pubs/MRL-0004.pdf
• http://monerolink.com/monerolink.pdf