Ripple: How to calculate transaction ID (TXID)
The transaction ID is calculated by prepending the bytes 0x54, 0x58, 0x4e, 0x00 to the signed transaction and then taking the SHA512Half of this input.
Example for a signed transaction, bytes are represented as hex strings:
txBlob = &quot;120000228000000024000000026140000000017d64b86840000000000013887321032c03bf7001689bebbb90e79c42deb99bf71be31f7460c1ce66a244635417b35a7446304402205ec87865bb0da66d71d0700ee2dfb901b458da4d32f43a51cf22f331273022d9022013dcb672d61eb53d28cd0c4069a0d12c03c70efc304d65b3665d8ba76c3477288114985d8d3734809d8be363675897ae4a711f1be06483144a3031789de7672be61cb3a5d200ecee0b8e462f&quot;

inserting the prefix yields
txid = SHA512Half(&quot;54584E00120000228000000024000000026140000000017d64b86840000000000013887321032c03bf7001689bebbb90e79c42deb99bf71be31f7460c1ce66a244635417b35a7446304402205ec87865bb0da66d71d0700ee2dfb901b458da4d32f43a51cf22f331273022d9022013dcb672d61eb53d28cd0c4069a0d12c03c70efc304d65b3665d8ba76c3477288114985d8d3734809d8be363675897ae4a711f1be06483144a3031789de7672be61cb3a5d200ecee0b8e462f&quot;)

txid = &quot;7ca5f7064a4054f0f0687431f5bac32798e06e51b51539687140ac6b5e82f9c7&quot;

SHA512Half is the first 32 bytes of the SHA512 output.
The example transaction above can be found here: