Double Spend Attacks on Exchanges

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20 confirmations are not enough to defend the attack! Switch to 50 or higher.

The latest attack happened 45 hours ago.

  {
    "height": 529105,
    "hash": "0000000023ad92fe3c2cf28f0d64e4eebdfef57f08872edab57398aea8ce0589",
    "branchlen": 1,
    "status": "valid-fork"
  },
  {
    "height": 529064,
    "hash": "00000000155e2435fee41d84f57f6f9877c534b86c77bf8eeea6e67259da34b3",
    "branchlen": 1,
    "status": "valid-fork"
  },
  {
    "height": 529052,
    "hash": "000000000f5bb9fd2980dcf1f995cd295322f67f1a8fead4422b11b37eae510d",
    "branchlen": 1,
    "status": "valid-fork"
  },
  {
    "height": 529043,
    "hash": "000000001783db4c9bcc58c4c28c517bf839b785ac02a836d42ce6438def5684",
    "branchlen": 22,
    "status": "valid-fork"
  },

The first 3 branches don’t contain any double spending transaction but the final one does. The attacker successfully revert a chain with 22 blocks by a longer chain with 25 blocks!

So 20 confirmations are not enough to prevent a double spending.

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