Each coinflip gets a random winningNumber generated at creation. Then it is hashed and displayed for the players:
$winningNumber = "";
$salt = "";
$hash = md5($winningNumber ."*". $salt);;
You can verify hash values here:

Date Hash Salt Winning Number Winner side
2018-03-18 14:11:58 8a824b801ebe06aa441cbbcef4e5bbd8 vVeX90Ei1oX4KXvJ 35719
2018-03-17 14:06:33 5c8925311e7671b24aeb8e4f4e4797e8 nwCTED5QCWX7gSzM 70914
2018-03-17 21:51:51 da0fad309d249db413f9a95f9b41c437 Rwnfhsepg0iQmzzs 41952
2018-03-17 00:04:06 955f99442517ed73f05c83817a7cbbca JkstsDsUh388N8um 6182
2018-03-16 17:50:19 223ced63266502eb0820848cd272c4fe 5V06O5UQteZdtz5m 51437
2018-03-16 16:10:38 51942225adca3ee77cc9987b255d7ad8 okas46enVji4uhal 28987
2018-03-15 22:59:41 2db2e055576d42abe93b468bc336106f 7UuoluheRKNSP9Ko 31858
2018-03-15 21:27:53 d7d0d1850e3b72bbd1d8606a04ece6d0 R3JzxjKtmaZh9oLl 93297
2018-03-15 21:27:37 3ed6d2f3a3315ab68ce978f3655e9fd4 2hpdTZ5ZzdZ2rEGw 54165
2018-03-14 15:48:11 d0283609244a856351dd325765ce7d60 Rgh9QL1Vd3GF6cn1 34850
2018-03-14 02:22:27 bbddb6f4af0347b1740a24d126d40216 xYUjgiiseLViXxxN 87843
2018-03-14 02:21:54 db168f23755a17eb7d79d8f9f3e9e02e npYgWGigxWPNSIkc 97512
2018-03-12 18:10:56 25255b303089f366c15abd9b4c0e8f59 Yw4NwTyArgADbJEq 96728
2018-03-12 15:58:04 46c4cf6b68d70c0490fc1b6506d11ce8 fJwfDiIi592kbf4A 74603
2018-03-12 15:57:56 8774c05995dc9169fae0314dfb98cce1 EFPBqbHtYmEdi1Xo 89853
2018-03-12 15:58:11 c09b09f3f6c86e4f440fdaae80c4f934 vzYxnCfGIjln80TP 96922
2018-03-12 14:12:15 a23aebcaa1419ec59f2a95a56ef098a7 xPglfsMywnb2TNly 90004
2018-03-12 13:21:27 6de69b8ff24992b57c242e0d7ea22b2c 4Su6uh2ccUuGmQmq 38678
2018-03-12 01:41:20 caefbfe503d278b5d0aa29127ea9ed50 rTOKpxV9Jtjm3mJe 58689
2018-03-11 22:12:49 178bf22ee3686ee6f48f4fe9ffc843b4 9Demh9T0WwqK0m5E 96583
2018-03-11 19:03:28 36c1848ace94c399080848c497596966 uxEHmLtLpVhgqIMd 88559
2018-03-11 16:26:17 db82809bd369f2d20155c8f754d9e969 qXQufInSbM3Yk7YQ 86470
2018-03-09 23:20:19 3afe3386784b2e5c3a5f7d4f98a0b6e9 xoEkIHJx4sY0XpDw 50386
2018-03-09 23:20:05 67fd673765b77493ff9a8f9057cc36d7 nop2G19o6Z0bSvNl 73373
2018-03-09 21:21:52 02e8c3e576ce2f7a7e850484c3d4da37 1vVarEtQmopyoH3z 13927
2018-03-09 15:44:29 5d598bcfdd766799756222334d65636e 15975PqVZXKfPgK7 22594
2018-03-09 04:35:24 9ee4dbf7ad088b09adcd9fcc3669afa9 q8imAytkeQ1HF4Zj 53847
2018-03-09 04:35:20 8a06e12e1a8c71fc999a9f2398f888d3 lGFh0i9foNv1mAvA 48241
2018-03-08 16:03:03 e9f3632550931c80baa09162e9e5a886 MVWBBv2b3n4CvzMq 44093
2018-03-08 16:02:52 109d833b6c73e4064c3563189127e35c s2b1vWtE1sGWrmlP 53201
2018-03-08 01:05:56 0e05b98de58a535122d478239941c3bf LfOsrhLQvUI5Lfk2 54578
2018-03-07 01:54:07 c981dec2af6537d2b9cfd7eef7c6c2b3 33bqQtbWsdecqcLD 31739
2018-03-06 20:32:16 f0265eed6a19ffda52df40ee32b92d03 YPEwtXLCIt57kXwT 9985
2018-03-05 22:23:42 ef0f1892f5c986a724aab28b7a09ca5a hAYdwFUjI8pBu432 11590
2018-03-04 11:56:46 c1ba04195de80a5075197720019fbbc8 9Y4tXtE2mKFZMw6K 58163
2018-02-27 05:35:06 7011f6ce6dba93456e8090971143d4fd 9JzKIZB3adBO32tD 79455
2018-02-25 02:40:36 6661803e00abe0c1ce549fb9e001161a W73mmXPbJ2GNlZ71 33973
2018-02-25 02:40:03 e7eb241e3301e0241f6b76061dae4f2f TzV7iEQHLaexBpab 88504
2018-02-25 02:39:41 834b71f02ec4ffd01734b7e91d17d94d wHpfjpJYgqROpVQX 2535
2018-02-25 02:39:17 f7a650187b5cd08a69024fa6039e58ae 6vMxQ9SR0H3Ijar9 77109
2018-02-23 09:13:48 d67ad2968f4fb87d449fa01962be428f xbKTFMDlz2gQMbOj 37208
2018-02-22 01:52:04 9a624b9b3131ebfcd1bcf607881da9fb sG0PaDX5CVYeeFMJ 88449
2018-02-22 01:51:51 b7332fc84c69b0da17ce12c7ade0c25e pmMxvXn4Hcxt3YV0 1102
2018-02-22 01:51:33 ff2811196d382ffd7980e4ef7337351d SfsIlVHnVSQqkK8j 66158
2018-02-21 11:16:57 51777c71cb2e8c33e8a63b1ef51cf2d4 jterzqpBCWDXE3sD 93289
2018-02-20 18:58:42 db4c79c6c7f0855af7ebc3ee6835fc50 58d8XzXjVLIRUZpw 13170
2018-02-20 17:45:06 4e83fd59bc79611a88bd187a244e2607 KpTa832xSPpM6aKf 19046
2018-02-19 19:53:39 7b54dc2ad84cf52e257441de26078471 ukae96GOiPTr5Ew8 11274
2018-02-19 17:47:11 3901922281f592085a92d61b583c3de6 OJs5UqbodTAYqrkn 48011
2018-02-18 19:29:49 05f5554c10227cb8101bc0125927a091 B42zGkr0VBfRbVdu 52930
2018-02-18 09:25:42 0858c86b5648a5cfd437fca4eebe1884 PaKGJfGDAxx4UNvN 43901
2018-02-18 01:44:43 ed789a5661b8613ff4dd1da2b1366ce6 iNKSwX7CCKzvIAvx 40921
2018-02-18 01:44:07 cf407fdc8ea76e9f4e59a094eea90277 sS2X7hbsVWV4x6nm 77135
2018-02-18 01:43:50 62678b786468165942245447a52e5d89 kLsD9OSWCHdet5Jg 48923
2018-02-18 01:43:19 2c0ffdf581b6aa9064ca069516566069 LcF5oTYrU8kKkuik 43322
2018-02-18 01:43:32 7a8611bc99082bbba8b2dceddc417c25 2KdseKOXwjX9gdvi 44606
2018-02-17 21:59:30 f16bc8dd8563fb5d9741cf56c9558938 MTf6zXBtPvGS6LeI 20222
2018-02-17 11:09:48 222ffdf7abe4733389bb828fb418ecfc KZE3Wt3NKVGNSw0S 96325
2018-02-15 18:13:58 63650ed07d59a4823d6a9d14c494f86a blMENKWBe63nHYns 53044
2018-02-14 19:30:32 9e2482508b594d91ceeb18a0c18950cd 14XqSLMStvspBgP3 86726
2018-02-14 07:40:17 aada5f203e7ad0755c5a5ce80273a4af R3CcMUcyoOfFYE2k 28795
2018-02-12 20:23:22 ad0137a668f774230804753411ed8d59 QAzXgtXfzzGggur8 88688
2018-02-12 18:45:47 394c48efb6e3a69363b8d30a060158e1 eDr8CpApjSZzS1RB 46798
2018-02-12 10:35:49 081c89449179c413d63bd7e6dc306ad1 1GLObCrRzFIyu79f 41773
2018-02-11 20:46:21 44e5311192827624114ca70b77ddc913 cjeduSN0KMMpPREc 29273
2018-02-11 12:43:37 516aedddbf695dbdce59f106ef57c8d6 aXBmdPgb2A15br2u 67267
2018-02-11 12:43:17 2e217c44fd27841e6f49b9dd60b51080 Fr0emyZ0RlN1b1Yk 42861
2018-02-11 12:43:01 ce65450dac351b0239d6889b996bad2e TQypech4t1y5qrM8 14004
2018-02-11 04:34:38 53b74d91f3ae769fda73e0739ff70696 6C0vc72MjLsEAB1L 85254
2018-02-09 18:55:22 cb21c9a5408e7e264646164d8e800aa9 rD4ke03wN9Fivj1p 85159
2018-02-09 00:52:07 1288d83ed31bd0702f49dee13db13646 f89jOAnKqY2ynELk 42824
2018-02-08 20:28:45 3ce1dc00fbc057f12fcf00330ed2fb0f AfAti8bmy6qHeMHx 60606
2018-02-07 20:36:17 6608b6ba2c4288b78ba8da071e3978a4 p2ezj0cONnvXtQlF 90173
2018-02-07 18:01:08 a1b0ec76e1184c07d3e4616677922f48 Xa41Vkf5IKFF0Cg1 69989
2018-02-07 15:09:19 4d7c6c5a71defb2c1c7a94345c996ba0 1Hwa1MmKXUkU81p1 17984
2018-02-06 19:32:41 13d31a24667324ab4f7f3785b4144fd6 rVjuMNe8iZ0dSiM7 10899
2018-02-05 21:19:35 82baac987c9d6eafb851e8d766ade541 Nv4ekpLiak4jLjz6 82510
2018-02-05 18:45:41 79eaef2354b92d383286123aaddfe840 krxSgMzXidLsytZt 32832
2018-02-05 18:45:13 79299f3a10647d29684f02f496804054 uB5jR1Zy5AHuvxuv 73801
2018-02-05 18:45:26 1325bf2a8488724af16ca1e25b2044f3 RQbrF8GgwQJxgZ9n 34311
2018-02-04 21:57:30 cb3a5bf0a1637bed960c6caeb41dada5 16FdpYLcAWKRyORM 21104
2018-02-04 20:25:52 cae67656346c77b22096a784616a7431 cS1UC3ibQpzck2m5 34119
2018-02-03 21:21:06 79eb33474b800b1b263cd720a8dba568 bb8YrGHLHb2A2Bko 55546
2018-02-03 17:04:49 6d6d2847169b1698c57dd3c1a1eccc26 zrYCcQ7xJGzGeFLc 63017
2018-02-03 17:04:33 0b5e66af1174db5256f1109a0997a547 KPXYT2oEu4mFc8fb 7449
2018-02-03 17:04:20 19e1d66d69773ae6d64903f3221f62de Sgsr2mdDlp7w2tar 32222
2018-02-03 17:03:58 ad2480e8c6dacd3a3d02cdc88414a644 VxEwOgMP8YGdtq8r 61622
2018-02-03 17:03:45 71ef524ceebdd6c9a848f29f11f6ffad kZG2TyoT7vvmDf58 890
2018-02-03 17:03:35 cf4247e12fb63d2a6a48b1cd5aaa50e1 kgMKJqgHNaxjXwmu 73733
2018-02-03 17:02:56 ffca1365ab7948e2da7b16a751d75506 62wcfEDeZWdAiGWD 80733
2018-02-03 17:02:35 4669ac0c9f27864844d0fe72144097a3 2cNti0mlPOmlrNU3 60550
2018-02-03 17:02:12 1bae340bf35e626a507f8446234895e3 ymdge44kNUXd2Nja 83111
2018-02-03 17:01:54 c7a0a56f51069f1f807009f49b5f44ed eJnkIzKtZK6WHRml 14726
2018-02-03 17:01:26 564757e7f06757ccb9b153ded64b16d7 4mOpHNGVVUWlolNk 13777
2018-02-03 17:01:09 197fbd2f51d049052ed64e7e2d1f826c t5Zws6AH74V8j05l 59061
2018-02-03 17:00:45 29f201c3c8c0f0b0cde1796e8a0d2125 HffWiBrFRRoEOOvq 41817
2018-02-03 16:58:40 042c022ff54520f63bc2394e8aefdbed 2kU0Gk0iNfaf4bBb 27662
2018-02-03 16:58:22 09f4e863b171dbcd338fbcf9aff00204 cOgmAuqP7MazMzC6 18138
2018-02-03 16:57:54 2715dc5fd07e39331a0dbcb339cdf78c oNkWUIpDBY2IlHCx 62086
2018-02-03 16:57:38 fb7c11d8997fd2884f4fbca814c59e6f sO3XRsncTbtzlp9L 75073